{
  "name": "US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side",
  "description": "Airborne exposure limits for workplace chemicals as stated by two independent authorities: federal OSHA's Table Z-1 (29 CFR 1910.1000) and California's own Table AC-1 (8 CCR 5155). Each record is one substance with the permissible exposure limit that agency publishes for it, the URL it came from and the verbatim table row it was read from. **The product is the disagreement**: where both regulate the same substance California is frequently stricter \u2014 acetaldehyde 200 ppm federally against 25 ppm in California, 1,1-dimethylhydrazine 0.5 against 0.01 \u2014 and exceeding a PEL is what triggers engineering controls, PPE and medical surveillance, so which number applies is consequential. Answers 'what is the exposure limit for [chemical]?', 'is the California PEL different from OSHA's?' and 'what is the PEL for acetone' \u2014 the questions where an assistant gives one number without saying whose it is.",
  "url": "https://referencesource.org/workplace-exposure-limits/",
  "licence": "US and California government works \u2014 public domain. ACGIH TLVs deliberately excluded (copyrighted). NIOSH RELs excluded: obtainable only second-hand.",
  "last_verified": "2026-08-05",
  "stale_after": "2027-08-05",
  "sources": [
    "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
    "https://www.dir.ca.gov/title8/5155.html"
  ],
  "records": [
    {
      "substance": "1,1,1,2-Tetrachloro-2,2-difluoroethane",
      "cas_number": "76-11-9",
      "pel_ppm": "500",
      "pel_mgm3": "4170",
      "id": "1-1-1-2-tetrachloro-2-2-difluoroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-1-2-tetrachloro-2-2-difluoroethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1,1,1,2-Tetrachloro-2,2-difluoroethane | 76-11-9 | 500 | 4170 | - |",
      "disagreements": []
    },
    {
      "substance": "1,1,1,-Trichloro-2,2-bis(p-chlorophenyl)ethane; see DDT",
      "id": "1-1-1-trichloro-2-2-bis-p-chlorophenyl-ethane-see-ddt",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-1-trichloro-2-2-bis-p-chlorophenyl-ethane-see-ddt/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "50293 | | 1,1,1,-Trichloro-2,2-bis(p-chlorophenyl)ethane; see DDT"
    },
    {
      "substance": "1,1,1-Trichloroethane; see Methyl chloroform",
      "id": "1-1-1-trichloroethane-see-methyl-chloroform",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-1-trichloroethane-see-methyl-chloroform/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "71556 | | 1,1,1-Trichloroethane; see Methyl chloroform"
    },
    {
      "substance": "1,1,2,2-Tetrabromoethane; see Acetylene tetrabromide",
      "id": "1-1-2-2-tetrabromoethane-see-acetylene-tetrabromide",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-2-2-tetrabromoethane-see-acetylene-tetrabromide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "79276 | | 1,1,2,2-Tetrabromoethane; see Acetylene tetrabromide"
    },
    {
      "substance": "1,1,2,2-Tetrachloro-1,2-difluoroethane",
      "cas_number": "76-12-0",
      "pel_ppm": "500",
      "pel_mgm3": "4170",
      "id": "1-1-2-2-tetrachloro-1-2-difluoroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-2-2-tetrachloro-1-2-difluoroethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1,1,2,2-Tetrachloro-1,2-difluoroethane | 76-12-0 | 500 | 4170 | - |"
    },
    {
      "substance": "1,1,2,2-Tetrachloro-1,2-difluoroethane; fluorocarbon 112",
      "pel_ppm": "500",
      "pel_mgm3": "4,170",
      "id": "1-1-2-2-tetrachloro-1-2-difluoroethane-fluorocarbon-112",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-2-2-tetrachloro-1-2-difluoroethane-fluorocarbon-112/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "76120 | | 1,1,2,2-Tetrachloro-1,2-difluoroethane; fluorocarbon 112 | 500 | 4,170"
    },
    {
      "substance": "1,1,2,2-Tetrachloroethane",
      "cas_number": "79-34-5",
      "pel_ppm": "5",
      "pel_mgm3": "35",
      "id": "1-1-2-2-tetrachloroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-2-2-tetrachloroethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1,1,2,2-Tetrachloroethane | 79-34-5 | 5 | 35 | X |"
    },
    {
      "substance": "1,1,2,2-Tetrachloroethane; acetylene tetrachloride",
      "pel_ppm": "1",
      "pel_mgm3": "7",
      "id": "1-1-2-2-tetrachloroethane-acetylene-tetrachloride",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-2-2-tetrachloroethane-acetylene-tetrachloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "79345 | S | 1,1,2,2-Tetrachloroethane; acetylene tetrachloride | 1 | 7"
    },
    {
      "substance": "1,1,2-Trichloro-1,2,2-trifluoroethane",
      "cas_number": "76-13-1",
      "pel_ppm": "1000",
      "pel_mgm3": "7600",
      "id": "1-1-2-trichloro-1-2-2-trifluoroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-2-trichloro-1-2-2-trifluoroethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1,1,2-Trichloro-1,2,2-trifluoroethane | 76-13-1 | 1000 | 7600 | - |",
      "disagreements": []
    },
    {
      "substance": "1,1,2-Trichloroethane",
      "cas_number": "79-00-5",
      "pel_ppm": "10",
      "pel_mgm3": "45",
      "id": "1-1-2-trichloroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-2-trichloroethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1,1,2-Trichloroethane | 79-00-5 | 10 | 45 | X |",
      "disagreements": []
    },
    {
      "substance": "1,1-Dichloro-1-nitroethane",
      "cas_number": "594-72-9",
      "pel_ppm": "(C)10",
      "pel_mgm3": "(C)60",
      "id": "1-1-dichloro-1-nitroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-dichloro-1-nitroethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1,1-Dichloro-1-nitroethane | 594-72-9 | (C)10 | (C)60 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "(C)10",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "1,1-Dichloro-1-nitroethane | 594-72-9 | (C)10 | (C)60 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "2",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "594729 | | 1,1-Dichloro-1-nitroethane | 2 | 10",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "(C)60",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "1,1-Dichloro-1-nitroethane | 594-72-9 | (C)10 | (C)60 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "10",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "594729 | | 1,1-Dichloro-1-nitroethane | 2 | 10",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "1,1-Dichloroethane",
      "cas_number": "75-34-3",
      "pel_ppm": "100",
      "pel_mgm3": "400",
      "id": "1-1-dichloroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-dichloroethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1,1-Dichloroethane | 75-34-3 | 100 | 400 | - |",
      "disagreements": []
    },
    {
      "substance": "1,1-Dichloroethylene; see Vinylidene chloride",
      "id": "1-1-dichloroethylene-see-vinylidene-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-dichloroethylene-see-vinylidene-chloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75354 | | 1,1-Dichloroethylene; see Vinylidene chloride"
    },
    {
      "substance": "1,1-Dimethylhydrazine",
      "cas_number": "57-14-7",
      "pel_ppm": "0.5",
      "pel_mgm3": "1",
      "id": "1-1-dimethylhydrazine",
      "url": "https://referencesource.org/workplace-exposure-limits/1-1-dimethylhydrazine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1,1-Dimethylhydrazine | 57-14-7 | 0.5 | 1 | X |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "0.5",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "1,1-Dimethylhydrazine | 57-14-7 | 0.5 | 1 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.01",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "57147 | S | 1,1-Dimethylhydrazine | 0.01 | 0.025",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "1",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "1,1-Dimethylhydrazine | 57-14-7 | 0.5 | 1 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.025",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "57147 | S | 1,1-Dimethylhydrazine | 0.01 | 0.025",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "1,2,3-Trichloropropane",
      "cas_number": "96-18-4",
      "pel_ppm": "50",
      "pel_mgm3": "300",
      "id": "1-2-3-trichloropropane",
      "url": "https://referencesource.org/workplace-exposure-limits/1-2-3-trichloropropane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1,2,3-Trichloropropane | 96-18-4 | 50 | 300 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "50",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "1,2,3-Trichloropropane | 96-18-4 | 50 | 300 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "10",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "96184 | | 1,2,3-Trichloropropane | 10 | 60",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "300",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "1,2,3-Trichloropropane | 96-18-4 | 50 | 300 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "60",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "96184 | | 1,2,3-Trichloropropane | 10 | 60",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "1,2,4-Trichlorobenzene",
      "pel_ppm": "5",
      "pel_mgm3": "40",
      "ceiling": "C",
      "id": "1-2-4-trichlorobenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/1-2-4-trichlorobenzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "120821 | | 1,2,4-Trichlorobenzene | 5 | 40 | C"
    },
    {
      "substance": "1,2-Diaminoethane; see Ethylenediamine Diatomacous earth; see Silica-amorphous",
      "id": "1-2-diaminoethane-see-ethylenediamine-diatomacous-earth-see-silica-amorphous",
      "url": "https://referencesource.org/workplace-exposure-limits/1-2-diaminoethane-see-ethylenediamine-diatomacous-earth-see-silica-amorphous/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107153 | | 1,2-Diaminoethane; see Ethylenediamine Diatomacous earth; see Silica-amorphous"
    },
    {
      "substance": "1,2-Dibromo-3-chloropropane (DBCP); see 1910.1044",
      "cas_number": "96-12-8",
      "id": "1-2-dibromo-3-chloropropane-dbcp-see-1910-1044",
      "url": "https://referencesource.org/workplace-exposure-limits/1-2-dibromo-3-chloropropane-dbcp-see-1910-1044/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1,2-Dibromo-3-chloropropane (DBCP); see 1910.1044 | 96-12-8 | - | - | - |"
    },
    {
      "substance": "1,2-Dibromo-3-chloropropane; DBCP; see Section 5212",
      "pel_ppm": ".001",
      "pel_mgm3": ".01",
      "id": "1-2-dibromo-3-chloropropane-dbcp-see-section-5212",
      "url": "https://referencesource.org/workplace-exposure-limits/1-2-dibromo-3-chloropropane-dbcp-see-section-5212/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "96128 | | 1,2-Dibromo-3-chloropropane; DBCP; see Section 5212 | .001 | .01"
    },
    {
      "substance": "1,2-Dibromoethane; see Ethylene dibromide, Section 5219",
      "id": "1-2-dibromoethane-see-ethylene-dibromide-section-5219",
      "url": "https://referencesource.org/workplace-exposure-limits/1-2-dibromoethane-see-ethylene-dibromide-section-5219/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106934 | S | 1,2-Dibromoethane; see Ethylene dibromide, Section 5219"
    },
    {
      "substance": "1,2-Dichloroethane, see Ethylene dichloride",
      "id": "1-2-dichloroethane-see-ethylene-dichloride",
      "url": "https://referencesource.org/workplace-exposure-limits/1-2-dichloroethane-see-ethylene-dichloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107062 | | 1,2-Dichloroethane, see Ethylene dichloride"
    },
    {
      "substance": "1,2-Dichloroethylene",
      "cas_number": "540-59-0",
      "pel_ppm": "200",
      "pel_mgm3": "790",
      "id": "1-2-dichloroethylene",
      "url": "https://referencesource.org/workplace-exposure-limits/1-2-dichloroethylene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1,2-Dichloroethylene | 540-59-0 | 200 | 790 | - |"
    },
    {
      "substance": "1,2-Dichloroethylene; acetylene dichloride",
      "pel_ppm": "200",
      "pel_mgm3": "790",
      "id": "1-2-dichloroethylene-acetylene-dichloride",
      "url": "https://referencesource.org/workplace-exposure-limits/1-2-dichloroethylene-acetylene-dichloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "540590 | | 1,2-Dichloroethylene; acetylene dichloride | 200 | 790"
    },
    {
      "substance": "1,2-Dichloropropane; see Propylene dichloride",
      "id": "1-2-dichloropropane-see-propylene-dichloride",
      "url": "https://referencesource.org/workplace-exposure-limits/1-2-dichloropropane-see-propylene-dichloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78875 | | 1,2-Dichloropropane; see Propylene dichloride"
    },
    {
      "substance": "1,2-Dichlorotetrafluoroethane; Fluorocarbon 114",
      "pel_ppm": "1,000",
      "pel_mgm3": "7,000",
      "id": "1-2-dichlorotetrafluoroethane-fluorocarbon-114",
      "url": "https://referencesource.org/workplace-exposure-limits/1-2-dichlorotetrafluoroethane-fluorocarbon-114/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "76142 | | 1,2-Dichlorotetrafluoroethane; Fluorocarbon 114 | 1,000 | 7,000"
    },
    {
      "substance": "1,2-Epoxypropane; see Propylene oxide",
      "id": "1-2-epoxypropane-see-propylene-oxide",
      "url": "https://referencesource.org/workplace-exposure-limits/1-2-epoxypropane-see-propylene-oxide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75569 | | 1,2-Epoxypropane; see Propylene oxide"
    },
    {
      "substance": "1,3,5-Triglycidyl-s-triazinetrione",
      "pel_mgm3": "0.005",
      "id": "1-3-5-triglycidyl-s-triazinetrione",
      "url": "https://referencesource.org/workplace-exposure-limits/1-3-5-triglycidyl-s-triazinetrione/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "2451629 | | 1,3,5-Triglycidyl-s-triazinetrione | | 0.005"
    },
    {
      "substance": "1,3-Butadiene (see also section 5201)",
      "pel_ppm": "1",
      "pel_mgm3": "2.2",
      "stel_ppm": "5",
      "stel_mgm3": "11",
      "id": "1-3-butadiene-see-also-section-5201",
      "url": "https://referencesource.org/workplace-exposure-limits/1-3-butadiene-see-also-section-5201/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106990 | | 1,3-Butadiene (see also section 5201) | 1 | 2.2 | | 5 | 11"
    },
    {
      "substance": "1,3-Dichloro-5,5-dimethyl hydantoin",
      "cas_number": "118-52-5",
      "pel_mgm3": "0.2",
      "id": "1-3-dichloro-5-5-dimethyl-hydantoin",
      "url": "https://referencesource.org/workplace-exposure-limits/1-3-dichloro-5-5-dimethyl-hydantoin/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1,3-Dichloro-5,5-dimethyl hydantoin | 118-52-5 | - | 0.2 | - |",
      "disagreements": []
    },
    {
      "substance": "1,3-Dimethylbutyl acetate; see sec-Hexyl acetate",
      "id": "1-3-dimethylbutyl-acetate-see-sec-hexyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/1-3-dimethylbutyl-acetate-see-sec-hexyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108849 | | 1,3-Dimethylbutyl acetate; see sec-Hexyl acetate"
    },
    {
      "substance": "1,4-Dichloro-2-butene",
      "pel_ppm": "0.005",
      "pel_mgm3": "0.025",
      "id": "1-4-dichloro-2-butene",
      "url": "https://referencesource.org/workplace-exposure-limits/1-4-dichloro-2-butene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "764410 | S | 1,4-Dichloro-2-butene | 0.005 | 0.025"
    },
    {
      "substance": "1,4-Diethylene dioxide; see p-Dioxane",
      "id": "1-4-diethylene-dioxide-see-p-dioxane",
      "url": "https://referencesource.org/workplace-exposure-limits/1-4-diethylene-dioxide-see-p-dioxane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "123911 | | 1,4-Diethylene dioxide; see p-Dioxane"
    },
    {
      "substance": "1,6-Hexanediamine",
      "pel_ppm": "0.5",
      "pel_mgm3": "2.3",
      "id": "1-6-hexanediamine",
      "url": "https://referencesource.org/workplace-exposure-limits/1-6-hexanediamine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "124094 | | 1,6-Hexanediamine | 0.5 | 2.3"
    },
    {
      "substance": "1-bromopropane, n-propyl bromide",
      "pel_ppm": "5",
      "pel_mgm3": "25",
      "id": "1-bromopropane-n-propyl-bromide",
      "url": "https://referencesource.org/workplace-exposure-limits/1-bromopropane-n-propyl-bromide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106945 | S | 1-bromopropane, n-propyl bromide | 5 | 25"
    },
    {
      "substance": "1-Butanethiol; see Butyl mercaptan",
      "id": "1-butanethiol-see-butyl-mercaptan",
      "url": "https://referencesource.org/workplace-exposure-limits/1-butanethiol-see-butyl-mercaptan/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "109795 | | 1-Butanethiol; see Butyl mercaptan"
    },
    {
      "substance": "1-Butanol; see n-Butyl alcohol",
      "id": "1-butanol-see-n-butyl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/1-butanol-see-n-butyl-alcohol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "71363 | | 1-Butanol; see n-Butyl alcohol"
    },
    {
      "substance": "1-Chloro-1-nitropropane",
      "cas_number": "600-25-9",
      "pel_ppm": "20",
      "pel_mgm3": "100",
      "id": "1-chloro-1-nitropropane",
      "url": "https://referencesource.org/workplace-exposure-limits/1-chloro-1-nitropropane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1-Chloro-1-nitropropane | 600-25-9 | 20 | 100 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "20",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "1-Chloro-1-nitropropane | 600-25-9 | 20 | 100 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "2",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "600259 | | 1-Chloro-1-nitropropane | 2 | 10",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "100",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "1-Chloro-1-nitropropane | 600-25-9 | 20 | 100 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "10",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "600259 | | 1-Chloro-1-nitropropane | 2 | 10",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "1-Chloro-2,3-epoxypropane; see Epichlorohydrin",
      "id": "1-chloro-2-3-epoxypropane-see-epichlorohydrin",
      "url": "https://referencesource.org/workplace-exposure-limits/1-chloro-2-3-epoxypropane-see-epichlorohydrin/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106898 | | 1-Chloro-2,3-epoxypropane; see Epichlorohydrin"
    },
    {
      "substance": "1-Chloro-4-nitrobenzene; see p-Nitrochlorobenzene",
      "id": "1-chloro-4-nitrobenzene-see-p-nitrochlorobenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/1-chloro-4-nitrobenzene-see-p-nitrochlorobenzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "100005 | | 1-Chloro-4-nitrobenzene; see p-Nitrochlorobenzene"
    },
    {
      "substance": "1-Hexene",
      "pel_ppm": "50",
      "pel_mgm3": "180",
      "id": "1-hexene",
      "url": "https://referencesource.org/workplace-exposure-limits/1-hexene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "592416 | | 1-Hexene | 50 | 180"
    },
    {
      "substance": "1-Naphthyl N-methylcarbamate; see Carbaryl",
      "id": "1-naphthyl-n-methylcarbamate-see-carbaryl",
      "url": "https://referencesource.org/workplace-exposure-limits/1-naphthyl-n-methylcarbamate-see-carbaryl/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "63252 | | 1-Naphthyl N-methylcarbamate; see Carbaryl"
    },
    {
      "substance": "1-Nitropropane",
      "cas_number": "108-03-2",
      "pel_ppm": "25",
      "pel_mgm3": "90",
      "id": "1-nitropropane",
      "url": "https://referencesource.org/workplace-exposure-limits/1-nitropropane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "1-Nitropropane | 108-03-2 | 25 | 90 | - |",
      "disagreements": []
    },
    {
      "substance": "2,2\u2032-Azobisisobutyronitrile decomposition product, see Tetramethyl succinonitrile",
      "id": "2-2-azobisisobutyronitrile-decomposition-product-see-tetramethyl-succinonitrile",
      "url": "https://referencesource.org/workplace-exposure-limits/2-2-azobisisobutyronitrile-decomposition-product-see-tetramethyl-succinonitrile/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "3333526 | S | 2,2\u2032-Azobisisobutyronitrile decomposition product, see Tetramethyl succinonitrile"
    },
    {
      "substance": "2,2-Dichloropropionic acid",
      "pel_ppm": "1",
      "pel_mgm3": "6",
      "id": "2-2-dichloropropionic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/2-2-dichloropropionic-acid/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75990 | | 2,2-Dichloropropionic acid | 1 | 6"
    },
    {
      "substance": "2,3-Epoxypropanol; see Glycidol",
      "id": "2-3-epoxypropanol-see-glycidol",
      "url": "https://referencesource.org/workplace-exposure-limits/2-3-epoxypropanol-see-glycidol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "556525 | | 2,3-Epoxypropanol; see Glycidol"
    },
    {
      "substance": "2,4,5-T (2,4,5-trichlorophenoxyacetic acid)",
      "cas_number": "93-76-5",
      "pel_mgm3": "10",
      "id": "2-4-5-t-2-4-5-trichlorophenoxyacetic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/2-4-5-t-2-4-5-trichlorophenoxyacetic-acid/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2,4,5-T (2,4,5-trichlorophenoxyacetic acid) | 93-76-5 | - | 10 | - |"
    },
    {
      "substance": "2,4,5-T;2,4,5-trichlorophenoxyacetic acid Talc; see Silicates",
      "pel_mgm3": "10",
      "id": "2-4-5-t-2-4-5-trichlorophenoxyacetic-acid-talc-see-silicates",
      "url": "https://referencesource.org/workplace-exposure-limits/2-4-5-t-2-4-5-trichlorophenoxyacetic-acid-talc-see-silicates/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "93765 | | 2,4,5-T;2,4,5-trichlorophenoxyacetic acid Talc; see Silicates | -- | 10"
    },
    {
      "substance": "2,4,5-Trichlorophenoxyacetic acid see 2,4,5-T",
      "id": "2-4-5-trichlorophenoxyacetic-acid-see-2-4-5-t",
      "url": "https://referencesource.org/workplace-exposure-limits/2-4-5-trichlorophenoxyacetic-acid-see-2-4-5-t/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "93765 | | 2,4,5-Trichlorophenoxyacetic acid see 2,4,5-T"
    },
    {
      "substance": "2,4,6-Trinitrophenol; see Picric acid",
      "id": "2-4-6-trinitrophenol-see-picric-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/2-4-6-trinitrophenol-see-picric-acid/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "88891 | | 2,4,6-Trinitrophenol; see Picric acid"
    },
    {
      "substance": "2,4,6-Trinitrophenylmethyl nitramine; see Tetryl",
      "id": "2-4-6-trinitrophenylmethyl-nitramine-see-tetryl",
      "url": "https://referencesource.org/workplace-exposure-limits/2-4-6-trinitrophenylmethyl-nitramine-see-tetryl/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "479458 | | 2,4,6-Trinitrophenylmethyl nitramine; see Tetryl"
    },
    {
      "substance": "2,4,6-Trinitrotoluene (TNT)",
      "cas_number": "118-96-7",
      "pel_mgm3": "1.5",
      "id": "2-4-6-trinitrotoluene-tnt",
      "url": "https://referencesource.org/workplace-exposure-limits/2-4-6-trinitrotoluene-tnt/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2,4,6-Trinitrotoluene (TNT) | 118-96-7 | - | 1.5 | X |"
    },
    {
      "substance": "2,4,6-Trinitrotoluene; TNT",
      "pel_mgm3": "0.5",
      "id": "2-4-6-trinitrotoluene-tnt-2",
      "url": "https://referencesource.org/workplace-exposure-limits/2-4-6-trinitrotoluene-tnt-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "118967 | S | 2,4,6-Trinitrotoluene; TNT | -- | 0.5"
    },
    {
      "substance": "2,4-D;2,4-dichlorophenoxyacetic acid",
      "pel_mgm3": "10",
      "id": "2-4-d-2-4-dichlorophenoxyacetic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/2-4-d-2-4-dichlorophenoxyacetic-acid/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "94757 | | 2,4-D;2,4-dichlorophenoxyacetic acid | -- | 10"
    },
    {
      "substance": "2,4-D (Dichlorophenoxyacetic acid)",
      "cas_number": "94-75-7",
      "pel_mgm3": "10",
      "id": "2-4-d-dichlorophenoxyacetic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/2-4-d-dichlorophenoxyacetic-acid/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2,4-D (Dichlorophenoxyacetic acid) | 94-75-7 | - | 10 | - |"
    },
    {
      "substance": "2,4-Dinitrotoluene",
      "pel_mgm3": "0.15",
      "id": "2-4-dinitrotoluene",
      "url": "https://referencesource.org/workplace-exposure-limits/2-4-dinitrotoluene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "25321146 | S | 2,4-Dinitrotoluene | -- | 0.15"
    },
    {
      "substance": "2,6-Di-tert-butyl-p-cresol",
      "pel_mgm3": "10",
      "id": "2-6-di-tert-butyl-p-cresol",
      "url": "https://referencesource.org/workplace-exposure-limits/2-6-di-tert-butyl-p-cresol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "128370 | | 2,6-Di-tert-butyl-p-cresol | -- | 10"
    },
    {
      "substance": "2,6-Dimethyl-4-heptanone; see Diisobutyl ketone",
      "id": "2-6-dimethyl-4-heptanone-see-diisobutyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/2-6-dimethyl-4-heptanone-see-diisobutyl-ketone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108838 | | 2,6-Dimethyl-4-heptanone; see Diisobutyl ketone"
    },
    {
      "substance": "2-Acetylaminofluorene; N-fluoren-2-yl acetamide; see Section 5209",
      "id": "2-acetylaminofluorene-n-fluoren-2-yl-acetamide-see-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/2-acetylaminofluorene-n-fluoren-2-yl-acetamide-see-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "53963 | S | 2-Acetylaminofluorene; N-fluoren-2-yl acetamide; see Section 5209"
    },
    {
      "substance": "2-Acetylaminofluorine; see 1910.1014",
      "cas_number": "53-96-3",
      "id": "2-acetylaminofluorine-see-1910-1014",
      "url": "https://referencesource.org/workplace-exposure-limits/2-acetylaminofluorine-see-1910-1014/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2-Acetylaminofluorine; see 1910.1014 | 53-96-3 | - | - | - |"
    },
    {
      "substance": "2-Aminoethanol; see Ethanolamine",
      "id": "2-aminoethanol-see-ethanolamine",
      "url": "https://referencesource.org/workplace-exposure-limits/2-aminoethanol-see-ethanolamine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "141435 | | 2-Aminoethanol; see Ethanolamine"
    },
    {
      "substance": "2-Aminonapthalene; see beta-Naphthylamine, Section 5209",
      "id": "2-aminonapthalene-see-beta-naphthylamine-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/2-aminonapthalene-see-beta-naphthylamine-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "91598 | | 2-Aminonapthalene; see beta-Naphthylamine, Section 5209"
    },
    {
      "substance": "2-Aminopyridine",
      "cas_number": "504-29-0",
      "pel_ppm": "0.5",
      "pel_mgm3": "2",
      "id": "2-aminopyridine",
      "url": "https://referencesource.org/workplace-exposure-limits/2-aminopyridine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2-Aminopyridine | 504-29-0 | 0.5 | 2 | - |",
      "disagreements": []
    },
    {
      "substance": "2-Butanone (Methyl ethyl ketone)",
      "cas_number": "78-93-3",
      "pel_ppm": "200",
      "pel_mgm3": "590",
      "id": "2-butanone-methyl-ethyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/2-butanone-methyl-ethyl-ketone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2-Butanone (Methyl ethyl ketone) | 78-93-3 | 200 | 590 | - |"
    },
    {
      "substance": "2-Butanone; see Methyl ethyl ketone",
      "id": "2-butanone-see-methyl-ethyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/2-butanone-see-methyl-ethyl-ketone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78933 | | 2-Butanone; see Methyl ethyl ketone"
    },
    {
      "substance": "2-Butoxyethanol",
      "cas_number": "111-76-2",
      "pel_ppm": "50",
      "pel_mgm3": "240",
      "id": "2-butoxyethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/2-butoxyethanol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2-Butoxyethanol | 111-76-2 | 50 | 240 | X |"
    },
    {
      "substance": "2-Butoxyethanol (EGBE)",
      "pel_ppm": "20",
      "pel_mgm3": "97",
      "id": "2-butoxyethanol-egbe",
      "url": "https://referencesource.org/workplace-exposure-limits/2-butoxyethanol-egbe/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "111762 | S | 2-Butoxyethanol (EGBE) | 20 | 97"
    },
    {
      "substance": "2-Chloro-1,3-butadiene; see Chloroprene",
      "id": "2-chloro-1-3-butadiene-see-chloroprene",
      "url": "https://referencesource.org/workplace-exposure-limits/2-chloro-1-3-butadiene-see-chloroprene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "126998 | S | 2-Chloro-1,3-butadiene; see Chloroprene"
    },
    {
      "substance": "2-Chloro-6-(trichloromethyl) pyridine",
      "cas_number": "1929-82-4",
      "id": "2-chloro-6-trichloromethyl-pyridine",
      "url": "https://referencesource.org/workplace-exposure-limits/2-chloro-6-trichloromethyl-pyridine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2-Chloro-6-(trichloromethyl) pyridine | 1929-82-4 | - | - | - |"
    },
    {
      "substance": "2-Chloro-6-(trichloromethyl)pyridine; see Nitrapyrin",
      "id": "2-chloro-6-trichloromethyl-pyridine-see-nitrapyrin",
      "url": "https://referencesource.org/workplace-exposure-limits/2-chloro-6-trichloromethyl-pyridine-see-nitrapyrin/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1929824 | | 2-Chloro-6-(trichloromethyl)pyridine; see Nitrapyrin | --"
    },
    {
      "substance": "2-Chloroethanol; see Ethylene chlorohydrin",
      "id": "2-chloroethanol-see-ethylene-chlorohydrin",
      "url": "https://referencesource.org/workplace-exposure-limits/2-chloroethanol-see-ethylene-chlorohydrin/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107073 | | 2-Chloroethanol; see Ethylene chlorohydrin"
    },
    {
      "substance": "2-Chloropropionic acid",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.44",
      "id": "2-chloropropionic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/2-chloropropionic-acid/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "598787 | S | 2-Chloropropionic acid | 0.1 | 0.44"
    },
    {
      "substance": "2-(Diethylamino) ethanol",
      "pel_ppm": "2",
      "pel_mgm3": "9.6",
      "id": "2-diethylamino-ethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/2-diethylamino-ethanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "100378 | S | 2-(Diethylamino) ethanol | 2 | 9.6"
    },
    {
      "substance": "2-Diethylaminoethanol",
      "cas_number": "100-37-8",
      "pel_ppm": "10",
      "pel_mgm3": "50",
      "id": "2-diethylaminoethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/2-diethylaminoethanol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2-Diethylaminoethanol | 100-37-8 | 10 | 50 | X |"
    },
    {
      "substance": "2-Ethoxyethanol",
      "pel_ppm": "5",
      "pel_mgm3": "18",
      "id": "2-ethoxyethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/2-ethoxyethanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "110805 | S | 2-Ethoxyethanol | 5 | 18"
    },
    {
      "substance": "2-Ethoxyethanol (Cellosolve)",
      "cas_number": "110-80-5",
      "pel_ppm": "200",
      "pel_mgm3": "740",
      "id": "2-ethoxyethanol-cellosolve",
      "url": "https://referencesource.org/workplace-exposure-limits/2-ethoxyethanol-cellosolve/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2-Ethoxyethanol (Cellosolve) | 110-80-5 | 200 | 740 | X |"
    },
    {
      "substance": "2-Ethoxyethyl acetate",
      "pel_ppm": "5",
      "pel_mgm3": "27",
      "id": "2-ethoxyethyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/2-ethoxyethyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "111159 | S | 2-Ethoxyethyl acetate | 5 | 27"
    },
    {
      "substance": "2-Ethoxyethyl acetate (Cellosolve acetate)",
      "cas_number": "111-15-9",
      "pel_ppm": "100",
      "pel_mgm3": "540",
      "id": "2-ethoxyethyl-acetate-cellosolve-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/2-ethoxyethyl-acetate-cellosolve-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2-Ethoxyethyl acetate (Cellosolve acetate) | 111-15-9 | 100 | 540 | X |"
    },
    {
      "substance": "2-Hexanone (Methyl n-butyl ketone)",
      "cas_number": "591-78-6",
      "pel_ppm": "100",
      "pel_mgm3": "410",
      "id": "2-hexanone-methyl-n-butyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/2-hexanone-methyl-n-butyl-ketone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2-Hexanone (Methyl n-butyl ketone) | 591-78-6 | 100 | 410 | - |"
    },
    {
      "substance": "2-Hexanone; see Methyl butyl ketone",
      "id": "2-hexanone-see-methyl-butyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/2-hexanone-see-methyl-butyl-ketone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "591786 | | 2-Hexanone; see Methyl butyl ketone"
    },
    {
      "substance": "2-Hydroxypropyl acrylate",
      "pel_ppm": "0.5",
      "pel_mgm3": "3",
      "id": "2-hydroxypropyl-acrylate",
      "url": "https://referencesource.org/workplace-exposure-limits/2-hydroxypropyl-acrylate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "999611 | S | 2-Hydroxypropyl acrylate | 0.5 | 3"
    },
    {
      "substance": "2-Methoxyethanol",
      "pel_ppm": "5",
      "pel_mgm3": "16",
      "id": "2-methoxyethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/2-methoxyethanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "109864 | S | 2-Methoxyethanol | 5 | 16"
    },
    {
      "substance": "2-Methoxyethanol (Methyl cellosolve)",
      "cas_number": "109-86-4",
      "pel_ppm": "25",
      "pel_mgm3": "80",
      "id": "2-methoxyethanol-methyl-cellosolve",
      "url": "https://referencesource.org/workplace-exposure-limits/2-methoxyethanol-methyl-cellosolve/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2-Methoxyethanol (Methyl cellosolve) | 109-86-4 | 25 | 80 | X |"
    },
    {
      "substance": "2-Methoxyethyl acetate",
      "pel_ppm": "5",
      "pel_mgm3": "24",
      "id": "2-methoxyethyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/2-methoxyethyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "110496 | | 2-Methoxyethyl acetate | 5 | 24"
    },
    {
      "substance": "2-Methoxyethyl acetate (Methyl cellosolve acetate)",
      "cas_number": "110-49-6",
      "pel_ppm": "25",
      "pel_mgm3": "120",
      "id": "2-methoxyethyl-acetate-methyl-cellosolve-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/2-methoxyethyl-acetate-methyl-cellosolve-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2-Methoxyethyl acetate (Methyl cellosolve acetate) | 110-49-6 | 25 | 120 | X |"
    },
    {
      "substance": "2-Methylbutyl acetate; see Pentyl acetate",
      "id": "2-methylbutyl-acetate-see-pentyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/2-methylbutyl-acetate-see-pentyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "624419 | | 2-Methylbutyl acetate; see Pentyl acetate"
    },
    {
      "substance": "2-Methylcyclopentadienyl manganese tricarbonyl, as Mn",
      "pel_mgm3": "0.2",
      "id": "2-methylcyclopentadienyl-manganese-tricarbonyl-as-mn",
      "url": "https://referencesource.org/workplace-exposure-limits/2-methylcyclopentadienyl-manganese-tricarbonyl-as-mn/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "12108133 | S | 2-Methylcyclopentadienyl manganese tricarbonyl, as Mn | -- | 0.2"
    },
    {
      "substance": "2-N-Dibutylaminoethanol",
      "pel_ppm": "2",
      "pel_mgm3": "14",
      "id": "2-n-dibutylaminoethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/2-n-dibutylaminoethanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "102818 | S | 2-N-Dibutylaminoethanol | 2 | 14"
    },
    {
      "substance": "2-Nitropropane",
      "cas_number": "79-46-9",
      "pel_ppm": "25",
      "pel_mgm3": "90",
      "id": "2-nitropropane",
      "url": "https://referencesource.org/workplace-exposure-limits/2-nitropropane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2-Nitropropane | 79-46-9 | 25 | 90 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "25",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "2-Nitropropane | 79-46-9 | 25 | 90 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "10",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "79469 | | 2-Nitropropane | 10 | 35",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "90",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "2-Nitropropane | 79-46-9 | 25 | 90 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "35",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "79469 | | 2-Nitropropane | 10 | 35",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "2-Pentanone (Methyl propyl ketone)",
      "cas_number": "107-87-9",
      "pel_ppm": "200",
      "pel_mgm3": "700",
      "id": "2-pentanone-methyl-propyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/2-pentanone-methyl-propyl-ketone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "2-Pentanone (Methyl propyl ketone) | 107-87-9 | 200 | 700 | - |"
    },
    {
      "substance": "2-Pentanone; see Methyl propyl ketone",
      "id": "2-pentanone-see-methyl-propyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/2-pentanone-see-methyl-propyl-ketone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107879 | | 2-Pentanone; see Methyl propyl ketone"
    },
    {
      "substance": "3,3'-Dichlorobenzidine; 4,4'-diamino-3,3'-dichlorobiphenyl; see Section 5209",
      "id": "3-3-dichlorobenzidine-4-4-diamino-3-3-dichlorobiphenyl-see-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/3-3-dichlorobenzidine-4-4-diamino-3-3-dichlorobiphenyl-see-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "91941 | S | 3,3'-Dichlorobenzidine; 4,4'-diamino-3,3'-dichlorobiphenyl; see Section 5209"
    },
    {
      "substance": "3-Amyl acetate; see Pentyl acetate",
      "id": "3-amyl-acetate-see-pentyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/3-amyl-acetate-see-pentyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "620111 | | 3-Amyl acetate; see Pentyl acetate"
    },
    {
      "substance": "3,\u2032-Dichlorobenzidine; see 1910.1007",
      "cas_number": "91-94-1",
      "id": "3-dichlorobenzidine-see-1910-1007",
      "url": "https://referencesource.org/workplace-exposure-limits/3-dichlorobenzidine-see-1910-1007/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "3,\u2032-Dichlorobenzidine; see 1910.1007 | 91-94-1 | - | - | - |"
    },
    {
      "substance": "4,4\u2032-Methylene bis(2-chloroaniline), see also Section 5215",
      "pel_mgm3": "0.01",
      "id": "4-4-methylene-bis-2-chloroaniline-see-also-section-5215",
      "url": "https://referencesource.org/workplace-exposure-limits/4-4-methylene-bis-2-chloroaniline-see-also-section-5215/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "101144 | S | 4,4\u2032-Methylene bis(2-chloroaniline), see also Section 5215 | -- | 0.01"
    },
    {
      "substance": "4,4\u2032-Methylene dianiline; MDA (see also Sections 1535 & 5200)",
      "pel_ppm": "0.01",
      "pel_mgm3": "0.08",
      "stel_ppm": "0.1",
      "stel_mgm3": "0.8",
      "id": "4-4-methylene-dianiline-mda-see-also-sections-1535-5200",
      "url": "https://referencesource.org/workplace-exposure-limits/4-4-methylene-dianiline-mda-see-also-sections-1535-5200/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "101779 | S | 4,4\u2032-Methylene dianiline; MDA (see also Sections 1535 & 5200) | 0.01 | 0.08 | | 0.1 | 0.8"
    },
    {
      "substance": "4,4\u2032-Thiobis (6-tert, Butyl-m-cresol)",
      "cas_number": "96-69-5",
      "id": "4-4-thiobis-6-tert-butyl-m-cresol",
      "url": "https://referencesource.org/workplace-exposure-limits/4-4-thiobis-6-tert-butyl-m-cresol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "4,4\u2032-Thiobis (6-tert, Butyl-m-cresol) | 96-69-5 | - | - | - |"
    },
    {
      "substance": "4,4\u2032-Thiobis(6-tert-butyl-m-cresol",
      "id": "4-4-thiobis-6-tert-butyl-m-cresol-2",
      "url": "https://referencesource.org/workplace-exposure-limits/4-4-thiobis-6-tert-butyl-m-cresol-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "96695 | | 4,4\u2032-Thiobis(6-tert-butyl-m-cresol | --"
    },
    {
      "substance": "4,6-Dinitro-o-cresol; 2-methyl-4,6-dinitrophenol",
      "pel_mgm3": "0.2",
      "id": "4-6-dinitro-o-cresol-2-methyl-4-6-dinitrophenol",
      "url": "https://referencesource.org/workplace-exposure-limits/4-6-dinitro-o-cresol-2-methyl-4-6-dinitrophenol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "534521 | S | 4,6-Dinitro-o-cresol; 2-methyl-4,6-dinitrophenol | -- | 0.2"
    },
    {
      "substance": "4-Aminodiphenyl; see 1910.1011",
      "cas_number": "92-67-1",
      "id": "4-aminodiphenyl-see-1910-1011",
      "url": "https://referencesource.org/workplace-exposure-limits/4-aminodiphenyl-see-1910-1011/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "4-Aminodiphenyl; see 1910.1011 | 92-67-1 | - | - | - |"
    },
    {
      "substance": "4-Aminodiphenyl; see Section 5209",
      "id": "4-aminodiphenyl-see-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/4-aminodiphenyl-see-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "92671 | S | 4-Aminodiphenyl; see Section 5209"
    },
    {
      "substance": "4-Dimethylaminoazobenzene; see 1910.1015",
      "cas_number": "60-11-7",
      "id": "4-dimethylaminoazobenzene-see-1910-1015",
      "url": "https://referencesource.org/workplace-exposure-limits/4-dimethylaminoazobenzene-see-1910-1015/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "4-Dimethylaminoazobenzene; see 1910.1015 | 60-11-7 | - | - | - |"
    },
    {
      "substance": "4-Dimethylaminoazobenzene, see Section 5209",
      "id": "4-dimethylaminoazobenzene-see-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/4-dimethylaminoazobenzene-see-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "60117 | | 4-Dimethylaminoazobenzene, see Section 5209"
    },
    {
      "substance": "4-Methoxyphenol",
      "pel_mgm3": "5",
      "id": "4-methoxyphenol",
      "url": "https://referencesource.org/workplace-exposure-limits/4-methoxyphenol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "150765 | | 4-Methoxyphenol | -- | 5"
    },
    {
      "substance": "4-Nitrodiphenyl; see 1910.1003",
      "cas_number": "92-93-3",
      "id": "4-nitrodiphenyl-see-1910-1003",
      "url": "https://referencesource.org/workplace-exposure-limits/4-nitrodiphenyl-see-1910-1003/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "4-Nitrodiphenyl; see 1910.1003 | 92-93-3 | - | - | - |"
    },
    {
      "substance": "4-Nitrodiphenyl, see Section 5209",
      "id": "4-nitrodiphenyl-see-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/4-nitrodiphenyl-see-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "92933 | | 4-Nitrodiphenyl, see Section 5209"
    },
    {
      "substance": "4-Vinyl cyclohexene",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.4",
      "id": "4-vinyl-cyclohexene",
      "url": "https://referencesource.org/workplace-exposure-limits/4-vinyl-cyclohexene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "100403 | S | 4-Vinyl cyclohexene | 0.1 | 0.4"
    },
    {
      "substance": "a-Chloroacetophenone (Phenacyl chloride)",
      "cas_number": "532-27-4",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.3",
      "id": "a-chloroacetophenone-phenacyl-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/a-chloroacetophenone-phenacyl-chloride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "a-Chloroacetophenone (Phenacyl chloride) | 532-27-4 | 0.05 | 0.3 | - |"
    },
    {
      "substance": "Acetaldehyde",
      "cas_number": "75-07-0",
      "pel_ppm": "200",
      "pel_mgm3": "360",
      "id": "acetaldehyde",
      "url": "https://referencesource.org/workplace-exposure-limits/acetaldehyde/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Acetaldehyde | 75-07-0 | 200 | 360 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "200",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Acetaldehyde | 75-07-0 | 200 | 360 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "25",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "75070 | | Acetaldehyde | 25 | 45 | C",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "360",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Acetaldehyde | 75-07-0 | 200 | 360 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "45",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "75070 | | Acetaldehyde | 25 | 45 | C",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Acetic acid",
      "cas_number": "64-19-7",
      "pel_ppm": "10",
      "pel_mgm3": "25",
      "id": "acetic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/acetic-acid/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Acetic acid | 64-19-7 | 10 | 25 | - |",
      "disagreements": []
    },
    {
      "substance": "Acetic anhydride",
      "cas_number": "108-24-7",
      "pel_ppm": "5",
      "pel_mgm3": "20",
      "id": "acetic-anhydride",
      "url": "https://referencesource.org/workplace-exposure-limits/acetic-anhydride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Acetic anhydride | 108-24-7 | 5 | 20 | - |",
      "disagreements": [
        {
          "field": "substance",
          "versions": [
            {
              "value": "Acetic anhydride",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Acetic anhydride | 108-24-7 | 5 | 20 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "Acetic Anhydride",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "108247 | | Acetic Anhydride | 5 | 20 | C",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Acetone",
      "cas_number": "67-64-1",
      "pel_ppm": "1000",
      "pel_mgm3": "2400",
      "id": "acetone",
      "url": "https://referencesource.org/workplace-exposure-limits/acetone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Acetone | 67-64-1 | 1000 | 2400 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "1000",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Acetone | 67-64-1 | 1000 | 2400 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "500",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "67641 | | Acetone | 500 | 1200 | 3000 ppm | 750 | 1780",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "2400",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Acetone | 67-64-1 | 1000 | 2400 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1200",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "67641 | | Acetone | 500 | 1200 | 3000 ppm | 750 | 1780",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Acetone cyanohydrin as CN",
      "pel_ppm": "4.7",
      "pel_mgm3": "5",
      "ceiling": "C",
      "id": "acetone-cyanohydrin-as-cn",
      "url": "https://referencesource.org/workplace-exposure-limits/acetone-cyanohydrin-as-cn/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75865 | | Acetone cyanohydrin as CN | 4.7 | 5 | C"
    },
    {
      "substance": "Acetonitrile",
      "cas_number": "75-05-8",
      "pel_ppm": "40",
      "pel_mgm3": "70",
      "id": "acetonitrile",
      "url": "https://referencesource.org/workplace-exposure-limits/acetonitrile/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Acetonitrile | 75-05-8 | 40 | 70 | - |",
      "disagreements": []
    },
    {
      "substance": "Acetophenone",
      "pel_ppm": "10",
      "pel_mgm3": "49",
      "id": "acetophenone",
      "url": "https://referencesource.org/workplace-exposure-limits/acetophenone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "98862 | | Acetophenone | 10 | 49"
    },
    {
      "substance": "Acetylene",
      "id": "acetylene",
      "url": "https://referencesource.org/workplace-exposure-limits/acetylene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74862 | | Acetylene | (h)"
    },
    {
      "substance": "Acetylene dichloride; see 1,2-Dichloroethylene",
      "id": "acetylene-dichloride-see-1-2-dichloroethylene",
      "url": "https://referencesource.org/workplace-exposure-limits/acetylene-dichloride-see-1-2-dichloroethylene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "540590 | | Acetylene dichloride; see 1,2-Dichloroethylene"
    },
    {
      "substance": "Acetylene tetrabromide",
      "cas_number": "79-27-6",
      "pel_ppm": "1",
      "pel_mgm3": "14",
      "id": "acetylene-tetrabromide",
      "url": "https://referencesource.org/workplace-exposure-limits/acetylene-tetrabromide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Acetylene tetrabromide | 79-27-6 | 1 | 14 | - |"
    },
    {
      "substance": "Acetylene tetrabromide: 1,1,2,2-tetrabromoethane",
      "pel_ppm": "1",
      "pel_mgm3": "14",
      "id": "acetylene-tetrabromide-1-1-2-2-tetrabromoethane",
      "url": "https://referencesource.org/workplace-exposure-limits/acetylene-tetrabromide-1-1-2-2-tetrabromoethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "79276 | | Acetylene tetrabromide: 1,1,2,2-tetrabromoethane | 1 | 14"
    },
    {
      "substance": "Acetylene tetrachloride; see 1,1,2,2-Tetrachloroethane",
      "id": "acetylene-tetrachloride-see-1-1-2-2-tetrachloroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/acetylene-tetrachloride-see-1-1-2-2-tetrachloroethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "79345 | | Acetylene tetrachloride; see 1,1,2,2-Tetrachloroethane"
    },
    {
      "substance": "Acetylsalicylic acid (Aspirin)",
      "pel_mgm3": "5",
      "id": "acetylsalicylic-acid-aspirin",
      "url": "https://referencesource.org/workplace-exposure-limits/acetylsalicylic-acid-aspirin/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "50782 | | Acetylsalicylic acid (Aspirin) | -- | 5"
    },
    {
      "substance": "Acrolein",
      "cas_number": "107-02-8",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.25",
      "id": "acrolein",
      "url": "https://referencesource.org/workplace-exposure-limits/acrolein/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Acrolein | 107-02-8 | 0.1 | 0.25 | - |",
      "disagreements": []
    },
    {
      "substance": "Acrylamide",
      "cas_number": "79-06-1",
      "pel_mgm3": "0.3",
      "id": "acrylamide",
      "url": "https://referencesource.org/workplace-exposure-limits/acrylamide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Acrylamide | 79-06-1 | - | 0.3 | X |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "0.3",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Acrylamide | 79-06-1 | - | 0.3 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.03",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "79061 | S | Acrylamide | -- | 0.03",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Acrylic acid",
      "pel_ppm": "2",
      "pel_mgm3": "5.9",
      "id": "acrylic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/acrylic-acid/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "79107 | S | Acrylic acid | 2 | 5.9"
    },
    {
      "substance": "Acrylonitrile; see 1910.1045",
      "cas_number": "107-13-1",
      "id": "acrylonitrile-see-1910-1045",
      "url": "https://referencesource.org/workplace-exposure-limits/acrylonitrile-see-1910-1045/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Acrylonitrile; see 1910.1045 | 107-13-1 | - | - | - |"
    },
    {
      "substance": "Acrylonitrile; see Section 5213",
      "pel_ppm": "2",
      "pel_mgm3": "4.5",
      "id": "acrylonitrile-see-section-5213",
      "url": "https://referencesource.org/workplace-exposure-limits/acrylonitrile-see-section-5213/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107131 | S | Acrylonitrile; see Section 5213 | 2 | 4.5"
    },
    {
      "substance": "Adipic acid",
      "pel_mgm3": "5",
      "id": "adipic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/adipic-acid/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "124049 | | Adipic acid | -- | 5"
    },
    {
      "substance": "Adiponitrile",
      "pel_ppm": "2",
      "pel_mgm3": "8.8",
      "id": "adiponitrile",
      "url": "https://referencesource.org/workplace-exposure-limits/adiponitrile/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "111693 | S | Adiponitrile | 2 | 8.8"
    },
    {
      "substance": "Aldrin",
      "cas_number": "309-00-2",
      "pel_mgm3": "0.25",
      "id": "aldrin",
      "url": "https://referencesource.org/workplace-exposure-limits/aldrin/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Aldrin | 309-00-2 | - | 0.25 | X |"
    },
    {
      "substance": "Aldrin; 1,2,3,4,10,10-hexachloro-1,4,4a,5,8,8a-hexahydro-endo-1,2-exo-5,8-dimethanonaphthalene",
      "pel_mgm3": "0.25",
      "id": "aldrin-1-2-3-4-10-10-hexachloro-1-4-4a-5-8-8a-hexahydro-endo-1-2-exo-5-8-dimetha",
      "url": "https://referencesource.org/workplace-exposure-limits/aldrin-1-2-3-4-10-10-hexachloro-1-4-4a-5-8-8a-hexahydro-endo-1-2-exo-5-8-dimetha/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "309002 | S | Aldrin; 1,2,3,4,10,10-hexachloro-1,4,4a,5,8,8a-hexahydro-endo-1,2-exo-5,8-dimethanonaphthalene | -- | 0.25"
    },
    {
      "substance": "Allyl alcohol",
      "cas_number": "107-18-6",
      "pel_ppm": "2",
      "pel_mgm3": "5",
      "id": "allyl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/allyl-alcohol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Allyl alcohol | 107-18-6 | 2 | 5 | X |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "2",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Allyl alcohol | 107-18-6 | 2 | 5 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "107186 | S | Allyl alcohol | 0.5 | 1.25 | | 4 | 10",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "5",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Allyl alcohol | 107-18-6 | 2 | 5 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1.25",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "107186 | S | Allyl alcohol | 0.5 | 1.25 | | 4 | 10",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Allyl chloride",
      "cas_number": "107-05-1",
      "pel_ppm": "1",
      "pel_mgm3": "3",
      "id": "allyl-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/allyl-chloride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Allyl chloride | 107-05-1 | 1 | 3 | - |",
      "disagreements": []
    },
    {
      "substance": "Allyl glycidyl ether (AGE)",
      "cas_number": "106-92-3",
      "pel_ppm": "(C)10",
      "pel_mgm3": "(C)45",
      "id": "allyl-glycidyl-ether-age",
      "url": "https://referencesource.org/workplace-exposure-limits/allyl-glycidyl-ether-age/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Allyl glycidyl ether (AGE) | 106-92-3 | (C)10 | (C)45 | - |"
    },
    {
      "substance": "Allyl glycidyl ether; AGE",
      "pel_ppm": "0.2",
      "pel_mgm3": "0.93",
      "id": "allyl-glycidyl-ether-age-2",
      "url": "https://referencesource.org/workplace-exposure-limits/allyl-glycidyl-ether-age-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106923 | S | Allyl glycidyl ether; AGE | 0.2 | 0.93"
    },
    {
      "substance": "Allyl propyl disulfide",
      "cas_number": "2179-59-1",
      "pel_ppm": "2",
      "pel_mgm3": "12",
      "id": "allyl-propyl-disulfide",
      "url": "https://referencesource.org/workplace-exposure-limits/allyl-propyl-disulfide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Allyl propyl disulfide | 2179-59-1 | 2 | 12 | - |",
      "disagreements": []
    },
    {
      "substance": "alpha-Alumina",
      "cas_number": "1344-28-1",
      "id": "alpha-alumina",
      "url": "https://referencesource.org/workplace-exposure-limits/alpha-alumina/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "alpha-Alumina | 1344-28-1 | - | - | - |"
    },
    {
      "substance": "alpha-Chloroacetophenone; phenacyl chloride",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.3",
      "id": "alpha-chloroacetophenone-phenacyl-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/alpha-chloroacetophenone-phenacyl-chloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "532274 | | alpha-Chloroacetophenone; phenacyl chloride | 0.05 | 0.3"
    },
    {
      "substance": "alpha-Methyl styrene",
      "cas_number": "98-83-9",
      "pel_ppm": "(C)100",
      "pel_mgm3": "(C)480",
      "id": "alpha-methyl-styrene",
      "url": "https://referencesource.org/workplace-exposure-limits/alpha-methyl-styrene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "alpha-Methyl styrene | 98-83-9 | (C)100 | (C)480 | - |"
    },
    {
      "substance": "alpha-Methylacrylonitrile",
      "pel_ppm": "1",
      "pel_mgm3": "3",
      "id": "alpha-methylacrylonitrile",
      "url": "https://referencesource.org/workplace-exposure-limits/alpha-methylacrylonitrile/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "126987 | S | alpha-Methylacrylonitrile | 1 | 3"
    },
    {
      "substance": "alpha-Methylstyrene; 1-methyl-1-phenylethene",
      "pel_ppm": "50",
      "pel_mgm3": "240",
      "stel_ppm": "100",
      "stel_mgm3": "485",
      "id": "alpha-methylstyrene-1-methyl-1-phenylethene",
      "url": "https://referencesource.org/workplace-exposure-limits/alpha-methylstyrene-1-methyl-1-phenylethene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "98839 | | alpha-Methylstyrene; 1-methyl-1-phenylethene | 50 | 240 | | 100 | 485"
    },
    {
      "substance": "alpha-Naphthylamine; 1-naphthylamine, see Section 5209",
      "id": "alpha-naphthylamine-1-naphthylamine-see-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/alpha-naphthylamine-1-naphthylamine-see-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "134327 | | alpha-Naphthylamine; 1-naphthylamine, see Section 5209"
    },
    {
      "substance": "alpha-Naphthylamine; see 1910.1004",
      "cas_number": "134-32-7",
      "id": "alpha-naphthylamine-see-1910-1004",
      "url": "https://referencesource.org/workplace-exposure-limits/alpha-naphthylamine-see-1910-1004/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "alpha-Naphthylamine; see 1910.1004 | 134-32-7 | - | - | - |"
    },
    {
      "substance": "Alumina; see Particulates not otherwise regulated",
      "id": "alumina-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/alumina-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1344281 | | Alumina; see Particulates not otherwise regulated"
    },
    {
      "substance": "Aluminum distearate",
      "pel_mgm3": "10",
      "id": "aluminum-distearate",
      "url": "https://referencesource.org/workplace-exposure-limits/aluminum-distearate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "300925 | | Aluminum distearate | -- | 10"
    },
    {
      "substance": "Aluminum, metal (as Al)",
      "cas_number": "7429-90-5",
      "id": "aluminum-metal-as-al",
      "url": "https://referencesource.org/workplace-exposure-limits/aluminum-metal-as-al/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Aluminum, metal (as Al) | 7429-90-5 | - | - | - |"
    },
    {
      "substance": "Aluminum stearate",
      "pel_mgm3": "10",
      "id": "aluminum-stearate",
      "url": "https://referencesource.org/workplace-exposure-limits/aluminum-stearate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7047849 | | Aluminum stearate | -- | 10"
    },
    {
      "substance": "Aluminum tristearate",
      "pel_mgm3": "10",
      "id": "aluminum-tristearate",
      "url": "https://referencesource.org/workplace-exposure-limits/aluminum-tristearate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "637127 | | Aluminum tristearate | -- | 10"
    },
    {
      "substance": "Aminodimethylbenzene; see Xylidene",
      "id": "aminodimethylbenzene-see-xylidene",
      "url": "https://referencesource.org/workplace-exposure-limits/aminodimethylbenzene-see-xylidene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1300738 | | Aminodimethylbenzene; see Xylidene"
    },
    {
      "substance": "Amitrole",
      "pel_mgm3": "0.2",
      "id": "amitrole",
      "url": "https://referencesource.org/workplace-exposure-limits/amitrole/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "61825 | | Amitrole | -- | 0.2"
    },
    {
      "substance": "Ammonia",
      "cas_number": "7664-41-7",
      "pel_ppm": "50",
      "pel_mgm3": "35",
      "id": "ammonia",
      "url": "https://referencesource.org/workplace-exposure-limits/ammonia/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ammonia | 7664-41-7 | 50 | 35 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "50",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Ammonia | 7664-41-7 | 50 | 35 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "25",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7664417 | | Ammonia | 25 | 18 | | 35 | 27",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "35",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Ammonia | 7664-41-7 | 50 | 35 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "18",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7664417 | | Ammonia | 25 | 18 | | 35 | 27",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Ammonium chloride fume",
      "pel_mgm3": "10",
      "stel_mgm3": "20",
      "id": "ammonium-chloride-fume",
      "url": "https://referencesource.org/workplace-exposure-limits/ammonium-chloride-fume/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "12125029 | | Ammonium chloride fume | -- | 10 | | -- | 20"
    },
    {
      "substance": "Ammonium perfluorooctanoate",
      "pel_mgm3": "0.01",
      "id": "ammonium-perfluorooctanoate",
      "url": "https://referencesource.org/workplace-exposure-limits/ammonium-perfluorooctanoate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "3825261 | S | Ammonium perfluorooctanoate | -- | 0.01"
    },
    {
      "substance": "Ammonium stearate",
      "pel_mgm3": "10",
      "id": "ammonium-stearate",
      "url": "https://referencesource.org/workplace-exposure-limits/ammonium-stearate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1002897 | | Ammonium stearate | -- | 10"
    },
    {
      "substance": "Ammonium sulfamate",
      "cas_number": "7773-06-0",
      "id": "ammonium-sulfamate",
      "url": "https://referencesource.org/workplace-exposure-limits/ammonium-sulfamate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ammonium sulfamate | 7773-06-0 | - | - | - |",
      "disagreements": []
    },
    {
      "substance": "Aniline",
      "pel_ppm": "2",
      "pel_mgm3": "7.6",
      "id": "aniline",
      "url": "https://referencesource.org/workplace-exposure-limits/aniline/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "62533 | S | Aniline | 2 | 7.6"
    },
    {
      "substance": "Aniline and homologs",
      "cas_number": "62-53-3",
      "pel_ppm": "5",
      "pel_mgm3": "19",
      "id": "aniline-and-homologs",
      "url": "https://referencesource.org/workplace-exposure-limits/aniline-and-homologs/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Aniline and homologs | 62-53-3 | 5 | 19 | X |"
    },
    {
      "substance": "Anisidine (o-, p-isomers)",
      "cas_number": "29191-52-4",
      "pel_mgm3": "0.5",
      "id": "anisidine-o-p-isomers",
      "url": "https://referencesource.org/workplace-exposure-limits/anisidine-o-p-isomers/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Anisidine (o-, p-isomers) | 29191-52-4 | - | 0.5 | X |"
    },
    {
      "substance": "Anisidine (ortho and para isomers)",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.5",
      "id": "anisidine-ortho-and-para-isomers",
      "url": "https://referencesource.org/workplace-exposure-limits/anisidine-ortho-and-para-isomers/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "29191524 | S | Anisidine (ortho and para isomers) | 0.1 | 0.5"
    },
    {
      "substance": "Antimony and compounds (as Sb)",
      "cas_number": "7440-36-0",
      "pel_mgm3": "0.5",
      "id": "antimony-and-compounds-as-sb",
      "url": "https://referencesource.org/workplace-exposure-limits/antimony-and-compounds-as-sb/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Antimony and compounds (as Sb) | 7440-36-0 | - | 0.5 | - |"
    },
    {
      "substance": "ANTU; 1-(1-naphthyl)-2-thiourea; Bantu; Rattrack",
      "pel_mgm3": "0.3",
      "id": "antu-1-1-naphthyl-2-thiourea-bantu-rattrack",
      "url": "https://referencesource.org/workplace-exposure-limits/antu-1-1-naphthyl-2-thiourea-bantu-rattrack/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "86884 | | ANTU; 1-(1-naphthyl)-2-thiourea; Bantu; Rattrack | -- | 0.3"
    },
    {
      "substance": "ANTU (alpha Naphthylthiourea)",
      "cas_number": "86-88-4",
      "pel_mgm3": "0.3",
      "id": "antu-alpha-naphthylthiourea",
      "url": "https://referencesource.org/workplace-exposure-limits/antu-alpha-naphthylthiourea/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "ANTU (alpha Naphthylthiourea) | 86-88-4 | - | 0.3 | - |"
    },
    {
      "substance": "Argon",
      "id": "argon",
      "url": "https://referencesource.org/workplace-exposure-limits/argon/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440371 | | Argon | (h)"
    },
    {
      "substance": "Arsenic and inorganic arsenic compounds; see also Section 5214",
      "pel_mgm3": "0.01",
      "id": "arsenic-and-inorganic-arsenic-compounds-see-also-section-5214",
      "url": "https://referencesource.org/workplace-exposure-limits/arsenic-and-inorganic-arsenic-compounds-see-also-section-5214/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440382 | | Arsenic and inorganic arsenic compounds; see also Section 5214 | | 0.01"
    },
    {
      "substance": "Arsenic, inorganic compounds (as As); see 1910.1018",
      "cas_number": "7440-38-2",
      "id": "arsenic-inorganic-compounds-as-as-see-1910-1018",
      "url": "https://referencesource.org/workplace-exposure-limits/arsenic-inorganic-compounds-as-as-see-1910-1018/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Arsenic, inorganic compounds (as As); see 1910.1018 | 7440-38-2 | - | - | - |"
    },
    {
      "substance": "Arsenic, organic compounds (as As)",
      "cas_number": "7440-38-2",
      "pel_mgm3": "0.5",
      "id": "arsenic-organic-compounds-as-as",
      "url": "https://referencesource.org/workplace-exposure-limits/arsenic-organic-compounds-as-as/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Arsenic, organic compounds (as As) | 7440-38-2 | - | 0.5 | - |"
    },
    {
      "substance": "Arsine",
      "cas_number": "7784-42-1",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.2",
      "id": "arsine",
      "url": "https://referencesource.org/workplace-exposure-limits/arsine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Arsine | 7784-42-1 | 0.05 | 0.2 | - |"
    },
    {
      "substance": "Arsine; AsH $3",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.2",
      "id": "arsine-ash-3",
      "url": "https://referencesource.org/workplace-exposure-limits/arsine-ash-3/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7784421 | | Arsine; AsH $3 | 0.05 | 0.2"
    },
    {
      "substance": "Asphalt (petroleum) fumes",
      "pel_mgm3": "5",
      "id": "asphalt-petroleum-fumes",
      "url": "https://referencesource.org/workplace-exposure-limits/asphalt-petroleum-fumes/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "8052424 | | Asphalt (petroleum) fumes | -- | 5"
    },
    {
      "substance": "Atrazine",
      "pel_mgm3": "5",
      "id": "atrazine",
      "url": "https://referencesource.org/workplace-exposure-limits/atrazine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1912249 | | Atrazine | -- | 5"
    },
    {
      "substance": "Azinphos-methyl",
      "cas_number": "86-50-0",
      "pel_mgm3": "0.2",
      "id": "azinphos-methyl",
      "url": "https://referencesource.org/workplace-exposure-limits/azinphos-methyl/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Azinphos-methyl | 86-50-0 | - | 0.2 | X |"
    },
    {
      "substance": "Azinphos methyl; o,o-dimethyl S-(4-oxo-1,2,3-benzotriazin-3(4H)-ylmethyl) phosphorodithioate",
      "pel_mgm3": "0.2",
      "id": "azinphos-methyl-o-o-dimethyl-s-4-oxo-1-2-3-benzotriazin-3-4h-ylmethyl-phosphorod",
      "url": "https://referencesource.org/workplace-exposure-limits/azinphos-methyl-o-o-dimethyl-s-4-oxo-1-2-3-benzotriazin-3-4h-ylmethyl-phosphorod/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "86500 | S | Azinphos methyl; o,o-dimethyl S-(4-oxo-1,2,3-benzotriazin-3(4H)-ylmethyl) phosphorodithioate | -- | 0.2"
    },
    {
      "substance": "Barium, soluble compounds (as Ba)",
      "cas_number": "7440-39-3",
      "pel_mgm3": "0.5",
      "id": "barium-soluble-compounds-as-ba",
      "url": "https://referencesource.org/workplace-exposure-limits/barium-soluble-compounds-as-ba/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Barium, soluble compounds (as Ba) | 7440-39-3 | - | 0.5 | - |"
    },
    {
      "substance": "Barium, soluble compounds, as Ba",
      "pel_mgm3": "0.5",
      "id": "barium-soluble-compounds-as-ba-2",
      "url": "https://referencesource.org/workplace-exposure-limits/barium-soluble-compounds-as-ba-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440393 | | Barium, soluble compounds, as Ba | -- | 0.5"
    },
    {
      "substance": "Barium sulfate",
      "cas_number": "7727-43-7",
      "id": "barium-sulfate",
      "url": "https://referencesource.org/workplace-exposure-limits/barium-sulfate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Barium sulfate | 7727-43-7 | - | - | - |"
    },
    {
      "substance": "Barium sulfate; see Particulates not otherwise regulated",
      "id": "barium-sulfate-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/barium-sulfate-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7727437 | | Barium sulfate; see Particulates not otherwise regulated"
    },
    {
      "substance": "Benomyl",
      "cas_number": "17804-35-2",
      "id": "benomyl",
      "url": "https://referencesource.org/workplace-exposure-limits/benomyl/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Benomyl | 17804-35-2 | - | - | - |",
      "disagreements": []
    },
    {
      "substance": "Benzene; see 1910.1028",
      "cas_number": "71-43-2",
      "id": "benzene-see-1910-1028",
      "url": "https://referencesource.org/workplace-exposure-limits/benzene-see-1910-1028/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Benzene; see 1910.1028 | 71-43-2 | - | - | - |"
    },
    {
      "substance": "Benzene; see also Section 5218",
      "pel_ppm": "1",
      "stel_ppm": "5",
      "id": "benzene-see-also-section-5218",
      "url": "https://referencesource.org/workplace-exposure-limits/benzene-see-also-section-5218/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "71432 | S | Benzene; see also Section 5218 | 1 | | | 5 | --"
    },
    {
      "substance": "Benzidine; 4,4\u2032-diaminobiphenyl, see Section 5209",
      "id": "benzidine-4-4-diaminobiphenyl-see-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/benzidine-4-4-diaminobiphenyl-see-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "92875 | S | Benzidine; 4,4\u2032-diaminobiphenyl, see Section 5209"
    },
    {
      "substance": "Benzidine; see 1910.1010",
      "cas_number": "92-87-5",
      "id": "benzidine-see-1910-1010",
      "url": "https://referencesource.org/workplace-exposure-limits/benzidine-see-1910-1010/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Benzidine; see 1910.1010 | 92-87-5 | - | - | - |"
    },
    {
      "substance": "Benzol; see Benzene",
      "id": "benzol-see-benzene",
      "url": "https://referencesource.org/workplace-exposure-limits/benzol-see-benzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "71432 | | Benzol; see Benzene"
    },
    {
      "substance": "Benzoyl chloride",
      "pel_ppm": "0.2",
      "pel_mgm3": "1.1",
      "ceiling": "C",
      "id": "benzoyl-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/benzoyl-chloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "98884 | | Benzoyl chloride | 0.2 | 1.1 | C"
    },
    {
      "substance": "Benzoyl peroxide",
      "cas_number": "94-36-0",
      "pel_mgm3": "5",
      "id": "benzoyl-peroxide",
      "url": "https://referencesource.org/workplace-exposure-limits/benzoyl-peroxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Benzoyl peroxide | 94-36-0 | - | 5 | - |"
    },
    {
      "substance": "Benzoyl peroxide; dibenzoyl peroxide",
      "pel_mgm3": "5",
      "id": "benzoyl-peroxide-dibenzoyl-peroxide",
      "url": "https://referencesource.org/workplace-exposure-limits/benzoyl-peroxide-dibenzoyl-peroxide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "94360 | | Benzoyl peroxide; dibenzoyl peroxide | -- | 5"
    },
    {
      "substance": "Benzyl acetate",
      "pel_ppm": "10",
      "pel_mgm3": "61",
      "id": "benzyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/benzyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "140114 | | Benzyl acetate | 10 | 61"
    },
    {
      "substance": "Benzyl chloride",
      "cas_number": "100-44-7",
      "pel_ppm": "1",
      "pel_mgm3": "5",
      "id": "benzyl-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/benzyl-chloride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Benzyl chloride | 100-44-7 | 1 | 5 | - |"
    },
    {
      "substance": "benzyl chloride; alpha-chlorotoluene",
      "pel_ppm": "0.03",
      "pel_mgm3": "0.16",
      "id": "benzyl-chloride-alpha-chlorotoluene",
      "url": "https://referencesource.org/workplace-exposure-limits/benzyl-chloride-alpha-chlorotoluene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "100447 | | benzyl chloride; alpha-chlorotoluene | 0.03 | 0.16"
    },
    {
      "substance": "Beryllium, and beryllium compounds",
      "pel_mgm3": "0.0002",
      "ceiling": "0.025mg/M 3",
      "stel_mgm3": "0.002",
      "id": "beryllium-and-beryllium-compounds",
      "url": "https://referencesource.org/workplace-exposure-limits/beryllium-and-beryllium-compounds/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440417 | | Beryllium, and beryllium compounds | -- | 0.0002 | 0.025mg/M 3 | -- | 0.002"
    },
    {
      "substance": "Beryllium and beryllium compounds (as Be); see 1926.1124 8",
      "cas_number": "7440-41-7",
      "id": "beryllium-and-beryllium-compounds-as-be-see-1926-1124-8",
      "url": "https://referencesource.org/workplace-exposure-limits/beryllium-and-beryllium-compounds-as-be-see-1926-1124-8/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Beryllium and beryllium compounds (as Be); see 1926.1124 8 | 7440-41-7 | - | - | - |"
    },
    {
      "substance": "beta-Chloroprene",
      "cas_number": "126-99-8",
      "pel_ppm": "25",
      "pel_mgm3": "90",
      "id": "beta-chloroprene",
      "url": "https://referencesource.org/workplace-exposure-limits/beta-chloroprene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "beta-Chloroprene | 126-99-8 | 25 | 90 | X |"
    },
    {
      "substance": "beta-Naphthylamine; 2-naphthylamine, see Section 5209",
      "id": "beta-naphthylamine-2-naphthylamine-see-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/beta-naphthylamine-2-naphthylamine-see-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "91598 | | beta-Naphthylamine; 2-naphthylamine, see Section 5209"
    },
    {
      "substance": "beta-Naphthylamine; see 1910.1009",
      "cas_number": "91-59-8",
      "id": "beta-naphthylamine-see-1910-1009",
      "url": "https://referencesource.org/workplace-exposure-limits/beta-naphthylamine-see-1910-1009/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "beta-Naphthylamine; see 1910.1009 | 91-59-8 | - | - | - |"
    },
    {
      "substance": "beta-Propiolactone, see Section 5209",
      "pel_ppm": "0.5",
      "pel_mgm3": "1.5",
      "id": "beta-propiolactone-see-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/beta-propiolactone-see-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "57578 | | beta-Propiolactone, see Section 5209 | 0.5 | 1.5"
    },
    {
      "substance": "beta-Propriolactone; see 1910.1013",
      "cas_number": "57-57-8",
      "id": "beta-propriolactone-see-1910-1013",
      "url": "https://referencesource.org/workplace-exposure-limits/beta-propriolactone-see-1910-1013/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "beta-Propriolactone; see 1910.1013 | 57-57-8 | - | - | - |"
    },
    {
      "substance": "Biphenyl; diphenyl; phenylbenzene",
      "pel_ppm": "0.2",
      "pel_mgm3": "1.5",
      "id": "biphenyl-diphenyl-phenylbenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/biphenyl-diphenyl-phenylbenzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "92524 | | Biphenyl; diphenyl; phenylbenzene | 0.2 | 1.5"
    },
    {
      "substance": "bis(Chloromethyl) ether; see 1910.1008",
      "cas_number": "542-88-1",
      "id": "bis-chloromethyl-ether-see-1910-1008",
      "url": "https://referencesource.org/workplace-exposure-limits/bis-chloromethyl-ether-see-1910-1008/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "bis(Chloromethyl) ether; see 1910.1008 | 542-88-1 | - | - | - |"
    },
    {
      "substance": "bis-Chloromethyl ether, see also Section 5209",
      "pel_ppm": "0.001",
      "pel_mgm3": "0.005",
      "id": "bis-chloromethyl-ether-see-also-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/bis-chloromethyl-ether-see-also-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "542881 | | bis-Chloromethyl ether, see also Section 5209 | 0.001 | 0.005"
    },
    {
      "substance": "Bis(chloromethyl) ether, see bis-Chloromethyl ether, Section 5209",
      "id": "bis-chloromethyl-ether-see-bis-chloromethyl-ether-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/bis-chloromethyl-ether-see-bis-chloromethyl-ether-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "542881 | | Bis(chloromethyl) ether, see bis-Chloromethyl ether, Section 5209"
    },
    {
      "substance": "Bis (Dimethylaminoethyl) ether (DMAEE)",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.328",
      "stel_ppm": "0.15",
      "stel_mgm3": "0.983",
      "id": "bis-dimethylaminoethyl-ether-dmaee",
      "url": "https://referencesource.org/workplace-exposure-limits/bis-dimethylaminoethyl-ether-dmaee/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "3033623 | S | Bis (Dimethylaminoethyl) ether (DMAEE) | 0.05 | 0.328 | | 0.15 | 0.983"
    },
    {
      "substance": "Bismuth telluride",
      "id": "bismuth-telluride",
      "url": "https://referencesource.org/workplace-exposure-limits/bismuth-telluride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1304821 | | Bismuth telluride"
    },
    {
      "substance": "Bismuth telluride, Undoped",
      "cas_number": "1304-82-1",
      "id": "bismuth-telluride-undoped",
      "url": "https://referencesource.org/workplace-exposure-limits/bismuth-telluride-undoped/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Bismuth telluride, Undoped | 1304-82-1 | - | - | - |"
    },
    {
      "substance": "Boron oxide",
      "cas_number": "1303-86-2",
      "id": "boron-oxide",
      "url": "https://referencesource.org/workplace-exposure-limits/boron-oxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Boron oxide | 1303-86-2 | - | - | - |",
      "disagreements": []
    },
    {
      "substance": "Boron tribromide",
      "pel_ppm": "1",
      "pel_mgm3": "10",
      "ceiling": "C",
      "id": "boron-tribromide",
      "url": "https://referencesource.org/workplace-exposure-limits/boron-tribromide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "10294334 | | Boron tribromide | 1 | 10 | C"
    },
    {
      "substance": "Boron trifluoride",
      "cas_number": "7637-07-2",
      "pel_ppm": "(C)1",
      "pel_mgm3": "(C)3",
      "id": "boron-trifluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/boron-trifluoride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Boron trifluoride | 7637-07-2 | (C)1 | (C)3 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "(C)1",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Boron trifluoride | 7637-07-2 | (C)1 | (C)3 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7637072 | | Boron trifluoride | 1 | 3 | C",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "(C)3",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Boron trifluoride | 7637-07-2 | (C)1 | (C)3 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "3",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7637072 | | Boron trifluoride | 1 | 3 | C",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Bromacil",
      "pel_ppm": "1",
      "pel_mgm3": "10",
      "id": "bromacil",
      "url": "https://referencesource.org/workplace-exposure-limits/bromacil/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "314409 | | Bromacil | 1 | 10"
    },
    {
      "substance": "Bromine",
      "cas_number": "7726-95-6",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.7",
      "id": "bromine",
      "url": "https://referencesource.org/workplace-exposure-limits/bromine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Bromine | 7726-95-6 | 0.1 | 0.7 | - |",
      "disagreements": []
    },
    {
      "substance": "Bromine pentafluoride",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.7",
      "id": "bromine-pentafluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/bromine-pentafluoride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7789302 | | Bromine pentafluoride | 0.1 | 0.7"
    },
    {
      "substance": "Bromochloromethane; see Chlorobromethane",
      "id": "bromochloromethane-see-chlorobromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/bromochloromethane-see-chlorobromethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74975 | | Bromochloromethane; see Chlorobromethane"
    },
    {
      "substance": "Bromoethane; see Ethyl bromide",
      "id": "bromoethane-see-ethyl-bromide",
      "url": "https://referencesource.org/workplace-exposure-limits/bromoethane-see-ethyl-bromide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74964 | | Bromoethane; see Ethyl bromide"
    },
    {
      "substance": "Bromoform",
      "cas_number": "75-25-2",
      "pel_ppm": "0.5",
      "pel_mgm3": "5",
      "id": "bromoform",
      "url": "https://referencesource.org/workplace-exposure-limits/bromoform/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Bromoform | 75-25-2 | 0.5 | 5 | X |"
    },
    {
      "substance": "Bromoform; tribromomethane",
      "pel_ppm": "0.5",
      "pel_mgm3": "5",
      "id": "bromoform-tribromomethane",
      "url": "https://referencesource.org/workplace-exposure-limits/bromoform-tribromomethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75252 | S | Bromoform; tribromomethane | 0.5 | 5"
    },
    {
      "substance": "Bromomethane, see Methyl bromide",
      "id": "bromomethane-see-methyl-bromide",
      "url": "https://referencesource.org/workplace-exposure-limits/bromomethane-see-methyl-bromide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74839 | | Bromomethane, see Methyl bromide"
    },
    {
      "substance": "Bromotrifluoromethane; see Trifluorobromomethane",
      "id": "bromotrifluoromethane-see-trifluorobromomethane",
      "url": "https://referencesource.org/workplace-exposure-limits/bromotrifluoromethane-see-trifluorobromomethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75638 | | Bromotrifluoromethane; see Trifluorobromomethane"
    },
    {
      "substance": "Butadiene (1,3-Butadiene); See 29 CFR 1910.1051; 29 CFR 1910.19(l)",
      "cas_number": "106-99-0",
      "pel_ppm": "1 ppm/5 ppm STEL",
      "id": "butadiene-1-3-butadiene-see-29-cfr-1910-1051-29-cfr-1910-19-l",
      "url": "https://referencesource.org/workplace-exposure-limits/butadiene-1-3-butadiene-see-29-cfr-1910-1051-29-cfr-1910-19-l/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Butadiene (1,3-Butadiene); See 29 CFR 1910.1051; 29 CFR 1910.19(l) | 106-99-0 | 1 ppm/5 ppm STEL | - | - |"
    },
    {
      "substance": "Butane",
      "pel_ppm": "800",
      "pel_mgm3": "1,900",
      "id": "butane",
      "url": "https://referencesource.org/workplace-exposure-limits/butane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106978 | | Butane | 800 | 1,900"
    },
    {
      "substance": "Butyl acrylate",
      "pel_ppm": "2",
      "pel_mgm3": "11",
      "id": "butyl-acrylate",
      "url": "https://referencesource.org/workplace-exposure-limits/butyl-acrylate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "141322 | | Butyl acrylate | 2 | 11"
    },
    {
      "substance": "Butyl mercaptan",
      "cas_number": "109-79-5",
      "pel_ppm": "10",
      "pel_mgm3": "35",
      "id": "butyl-mercaptan",
      "url": "https://referencesource.org/workplace-exposure-limits/butyl-mercaptan/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Butyl mercaptan | 109-79-5 | 10 | 35 | - |"
    },
    {
      "substance": "Butylamine",
      "cas_number": "109-73-9",
      "pel_ppm": "(C)5",
      "pel_mgm3": "(C)15",
      "id": "butylamine",
      "url": "https://referencesource.org/workplace-exposure-limits/butylamine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Butylamine | 109-73-9 | (C)5 | (C)15 | X |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "(C)5",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Butylamine | 109-73-9 | (C)5 | (C)15 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "109739 | S | Butylamine | 5 | 15 | C",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "(C)15",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Butylamine | 109-73-9 | (C)5 | (C)15 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "15",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "109739 | S | Butylamine | 5 | 15 | C",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Cadmium (as Cd); see 1910.1027",
      "cas_number": "7440-43-9",
      "id": "cadmium-as-cd-see-1910-1027",
      "url": "https://referencesource.org/workplace-exposure-limits/cadmium-as-cd-see-1910-1027/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Cadmium (as Cd); see 1910.1027 | 7440-43-9 | - | - | - |"
    },
    {
      "substance": "Cadmium metal dust, as Cd",
      "id": "cadmium-metal-dust-as-cd",
      "url": "https://referencesource.org/workplace-exposure-limits/cadmium-metal-dust-as-cd/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440439 | | Cadmium metal dust, as Cd"
    },
    {
      "substance": "Cadmium oxide fume, as Cd",
      "id": "cadmium-oxide-fume-as-cd",
      "url": "https://referencesource.org/workplace-exposure-limits/cadmium-oxide-fume-as-cd/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1306190 | | Cadmium oxide fume, as Cd"
    },
    {
      "substance": "Calcium arsenate; see Arsenic, inorganic (see also Section 5214)",
      "id": "calcium-arsenate-see-arsenic-inorganic-see-also-section-5214",
      "url": "https://referencesource.org/workplace-exposure-limits/calcium-arsenate-see-arsenic-inorganic-see-also-section-5214/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7778441 | | Calcium arsenate; see Arsenic, inorganic (see also Section 5214)"
    },
    {
      "substance": "Calcium carbonate",
      "cas_number": "1317-65-3",
      "id": "calcium-carbonate",
      "url": "https://referencesource.org/workplace-exposure-limits/calcium-carbonate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Calcium carbonate | 1317-65-3 | - | - | - |"
    },
    {
      "substance": "Calcium carbonate; see Particulates not otherwise regulated",
      "id": "calcium-carbonate-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/calcium-carbonate-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "471341 | | Calcium carbonate; see Particulates not otherwise regulated | --"
    },
    {
      "substance": "Calcium cyanamide",
      "pel_mgm3": "0.5",
      "id": "calcium-cyanamide",
      "url": "https://referencesource.org/workplace-exposure-limits/calcium-cyanamide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "156627 | | Calcium cyanamide | -- | 0.5"
    },
    {
      "substance": "Calcium hydroxide",
      "cas_number": "1305-62-0",
      "id": "calcium-hydroxide",
      "url": "https://referencesource.org/workplace-exposure-limits/calcium-hydroxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Calcium hydroxide | 1305-62-0 | - | - | - |",
      "disagreements": []
    },
    {
      "substance": "Calcium oxide",
      "cas_number": "1305-78-8",
      "pel_mgm3": "5",
      "id": "calcium-oxide",
      "url": "https://referencesource.org/workplace-exposure-limits/calcium-oxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Calcium oxide | 1305-78-8 | - | 5 | - |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "5",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Calcium oxide | 1305-78-8 | - | 5 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "2",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "1305788 | | Calcium oxide | -- | 2",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Calcium silicate",
      "cas_number": "1344-95-2",
      "id": "calcium-silicate",
      "url": "https://referencesource.org/workplace-exposure-limits/calcium-silicate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Calcium silicate | 1344-95-2 | - | - | - |"
    },
    {
      "substance": "Calcium silicate (synthetic): see Particulates not otherwise regulated",
      "id": "calcium-silicate-synthetic-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/calcium-silicate-synthetic-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1344952 | | Calcium silicate (synthetic): see Particulates not otherwise regulated"
    },
    {
      "substance": "Calcium stearate",
      "pel_mgm3": "10",
      "id": "calcium-stearate",
      "url": "https://referencesource.org/workplace-exposure-limits/calcium-stearate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1592230 | | Calcium stearate | -- | 10"
    },
    {
      "substance": "Calcium sulfate",
      "cas_number": "7778-18-9",
      "id": "calcium-sulfate",
      "url": "https://referencesource.org/workplace-exposure-limits/calcium-sulfate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Calcium sulfate | 7778-18-9 | - | - | - |"
    },
    {
      "substance": "Calcium sulfate; see Particulates not otherwise regulated",
      "id": "calcium-sulfate-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/calcium-sulfate-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7778189 | | Calcium sulfate; see Particulates not otherwise regulated"
    },
    {
      "substance": "Camphor, synthetic",
      "cas_number": "76-22-2",
      "pel_mgm3": "2",
      "id": "camphor-synthetic",
      "url": "https://referencesource.org/workplace-exposure-limits/camphor-synthetic/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Camphor, synthetic | 76-22-2 | - | 2 | - |"
    },
    {
      "substance": "Camphor (synthetic)",
      "pel_mgm3": "2",
      "id": "camphor-synthetic-2",
      "url": "https://referencesource.org/workplace-exposure-limits/camphor-synthetic-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "76222 | | Camphor (synthetic) | -- | 2"
    },
    {
      "substance": "Caprolactam dust",
      "pel_mgm3": "1",
      "stel_mgm3": "3",
      "id": "caprolactam-dust",
      "url": "https://referencesource.org/workplace-exposure-limits/caprolactam-dust/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "105602 | | Caprolactam dust | -- | 1 | | -- | 3"
    },
    {
      "substance": "Caprolactam vapor",
      "pel_ppm": "5",
      "pel_mgm3": "20",
      "stel_ppm": "10",
      "stel_mgm3": "40",
      "id": "caprolactam-vapor",
      "url": "https://referencesource.org/workplace-exposure-limits/caprolactam-vapor/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "105602 | | Caprolactam vapor | 5 | 20 | | 10 | 40"
    },
    {
      "substance": "Captafol",
      "pel_mgm3": "0.1",
      "id": "captafol",
      "url": "https://referencesource.org/workplace-exposure-limits/captafol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "2425061 | S | Captafol | -- | 0.1"
    },
    {
      "substance": "Captan",
      "pel_mgm3": "5",
      "id": "captan",
      "url": "https://referencesource.org/workplace-exposure-limits/captan/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "133062 | | Captan | -- | 5"
    },
    {
      "substance": "Carbaryl; 1-naphthyl N-methylcarbamate",
      "pel_mgm3": "5",
      "id": "carbaryl-1-naphthyl-n-methylcarbamate",
      "url": "https://referencesource.org/workplace-exposure-limits/carbaryl-1-naphthyl-n-methylcarbamate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "63252 | | Carbaryl; 1-naphthyl N-methylcarbamate | -- | 5"
    },
    {
      "substance": "Carbaryl (Sevin)",
      "cas_number": "63-25-2",
      "pel_mgm3": "5",
      "id": "carbaryl-sevin",
      "url": "https://referencesource.org/workplace-exposure-limits/carbaryl-sevin/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Carbaryl (Sevin) | 63-25-2 | - | 5 | - |"
    },
    {
      "substance": "Carbofuran",
      "pel_mgm3": "0.1",
      "id": "carbofuran",
      "url": "https://referencesource.org/workplace-exposure-limits/carbofuran/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1563662 | | Carbofuran | -- | 0.1"
    },
    {
      "substance": "Carbon black",
      "cas_number": "1333-86-4",
      "pel_mgm3": "3.5",
      "id": "carbon-black",
      "url": "https://referencesource.org/workplace-exposure-limits/carbon-black/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Carbon black | 1333-86-4 | - | 3.5 | - |",
      "disagreements": []
    },
    {
      "substance": "Carbon dioxide",
      "cas_number": "124-38-9",
      "pel_ppm": "5000",
      "pel_mgm3": "9000",
      "id": "carbon-dioxide",
      "url": "https://referencesource.org/workplace-exposure-limits/carbon-dioxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Carbon dioxide | 124-38-9 | 5000 | 9000 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "5000",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Carbon dioxide | 124-38-9 | 5000 | 9000 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "5,000",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "124389 | | Carbon dioxide | 5,000 | 9,000 | | 30,000 | 54,000",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "9000",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Carbon dioxide | 124-38-9 | 5000 | 9000 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "9,000",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "124389 | | Carbon dioxide | 5,000 | 9,000 | | 30,000 | 54,000",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Carbon disulfide",
      "cas_number": "75-15-0",
      "id": "carbon-disulfide",
      "url": "https://referencesource.org/workplace-exposure-limits/carbon-disulfide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Carbon disulfide | 75-15-0 | - | ( 2 ) | - |",
      "disagreements": []
    },
    {
      "substance": "Carbon monoxide",
      "cas_number": "630-08-0",
      "pel_ppm": "50",
      "pel_mgm3": "55",
      "id": "carbon-monoxide",
      "url": "https://referencesource.org/workplace-exposure-limits/carbon-monoxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Carbon monoxide | 630-08-0 | 50 | 55 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "50",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Carbon monoxide | 630-08-0 | 50 | 55 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "25",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "630080 | | Carbon monoxide | 25 | 29 | 200 ppm",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "55",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Carbon monoxide | 630-08-0 | 50 | 55 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "29",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "630080 | | Carbon monoxide | 25 | 29 | 200 ppm",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Carbon tetrabromide",
      "pel_ppm": "0.1",
      "pel_mgm3": "1.4",
      "stel_ppm": "0.3",
      "stel_mgm3": "4",
      "id": "carbon-tetrabromide",
      "url": "https://referencesource.org/workplace-exposure-limits/carbon-tetrabromide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "558134 | | Carbon tetrabromide | 0.1 | 1.4 | | 0.3 | 4"
    },
    {
      "substance": "Carbon tetrachloride",
      "cas_number": "56-23-5",
      "id": "carbon-tetrachloride",
      "url": "https://referencesource.org/workplace-exposure-limits/carbon-tetrachloride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Carbon tetrachloride | 56-23-5 | - | ( 2 ) | - |",
      "disagreements": []
    },
    {
      "substance": "Carbonyl chloride; see Phosgene",
      "id": "carbonyl-chloride-see-phosgene",
      "url": "https://referencesource.org/workplace-exposure-limits/carbonyl-chloride-see-phosgene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75445 | | Carbonyl chloride; see Phosgene"
    },
    {
      "substance": "Carbonyl fluoride",
      "pel_ppm": "2",
      "pel_mgm3": "5",
      "stel_ppm": "5",
      "stel_mgm3": "15",
      "id": "carbonyl-fluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/carbonyl-fluoride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "353504 | | Carbonyl fluoride | 2 | 5 | | 5 | 15"
    },
    {
      "substance": "Catechol; pyrocatechol",
      "pel_ppm": "5",
      "pel_mgm3": "20",
      "id": "catechol-pyrocatechol",
      "url": "https://referencesource.org/workplace-exposure-limits/catechol-pyrocatechol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "120809 | S | Catechol; pyrocatechol | 5 | 20"
    },
    {
      "substance": "Cellulose",
      "cas_number": "9004-34-6",
      "id": "cellulose",
      "url": "https://referencesource.org/workplace-exposure-limits/cellulose/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Cellulose | 9004-34-6 | - | - | - |"
    },
    {
      "substance": "Cellulose (paper fiber); see Particulates not otherwise regulated",
      "id": "cellulose-paper-fiber-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/cellulose-paper-fiber-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "9004346 | | Cellulose (paper fiber); see Particulates not otherwise regulated"
    },
    {
      "substance": "Cesium hydroxide",
      "pel_ppm": "2",
      "id": "cesium-hydroxide",
      "url": "https://referencesource.org/workplace-exposure-limits/cesium-hydroxide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "21351791 | | Cesium hydroxide | 2"
    },
    {
      "substance": "Chlordane",
      "cas_number": "57-74-9",
      "pel_mgm3": "0.5",
      "id": "chlordane",
      "url": "https://referencesource.org/workplace-exposure-limits/chlordane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chlordane | 57-74-9 | - | 0.5 | X |"
    },
    {
      "substance": "Chlordane; 1,2,4,5,6,7,8,8-octachloro-3a,4,7,7a-tetrahydro-4,7-methanoindane",
      "pel_mgm3": "0.5",
      "id": "chlordane-1-2-4-5-6-7-8-8-octachloro-3a-4-7-7a-tetrahydro-4-7-methanoindane",
      "url": "https://referencesource.org/workplace-exposure-limits/chlordane-1-2-4-5-6-7-8-8-octachloro-3a-4-7-7a-tetrahydro-4-7-methanoindane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "57749 | S | Chlordane; 1,2,4,5,6,7,8,8-octachloro-3a,4,7,7a-tetrahydro-4,7-methanoindane | -- | 0.5"
    },
    {
      "substance": "Chlorinated camphene",
      "cas_number": "8001-35-2",
      "pel_mgm3": "0.5",
      "id": "chlorinated-camphene",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorinated-camphene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chlorinated camphene | 8001-35-2 | - | 0.5 | X |"
    },
    {
      "substance": "Chlorinated camphene; toxaphene",
      "pel_mgm3": "0.5",
      "stel_mgm3": "1",
      "id": "chlorinated-camphene-toxaphene",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorinated-camphene-toxaphene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "8001352 | S | Chlorinated camphene; toxaphene | -- | 0.5 | | -- | 1"
    },
    {
      "substance": "Chlorinated diphenyl oxide",
      "cas_number": "55720-99-5",
      "pel_mgm3": "0.5",
      "id": "chlorinated-diphenyl-oxide",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorinated-diphenyl-oxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chlorinated diphenyl oxide | 55720-99-5 | - | 0.5 | - |"
    },
    {
      "substance": "Chlorine",
      "cas_number": "7782-50-5",
      "pel_ppm": "(C)1",
      "pel_mgm3": "(C)3",
      "id": "chlorine",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chlorine | 7782-50-5 | (C)1 | (C)3 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "(C)1",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Chlorine | 7782-50-5 | (C)1 | (C)3 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7782505 | | Chlorine | 0.5 | 1.5 | | 1 | 3",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "(C)3",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Chlorine | 7782-50-5 | (C)1 | (C)3 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1.5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7782505 | | Chlorine | 0.5 | 1.5 | | 1 | 3",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Chlorine dioxide",
      "cas_number": "10049-04-4",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.3",
      "id": "chlorine-dioxide",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorine-dioxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chlorine dioxide | 10049-04-4 | 0.1 | 0.3 | - |",
      "disagreements": []
    },
    {
      "substance": "Chlorine trifluoride",
      "cas_number": "7790-91-2",
      "pel_ppm": "(C)0.1",
      "pel_mgm3": "(C)0.4",
      "id": "chlorine-trifluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorine-trifluoride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chlorine trifluoride | 7790-91-2 | (C)0.1 | (C)0.4 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "(C)0.1",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Chlorine trifluoride | 7790-91-2 | (C)0.1 | (C)0.4 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7790912 | | Chlorine trifluoride | 0.1 | 0.4 | C",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "(C)0.4",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Chlorine trifluoride | 7790-91-2 | (C)0.1 | (C)0.4 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.4",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7790912 | | Chlorine trifluoride | 0.1 | 0.4 | C",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Chloroacetaldehyde",
      "cas_number": "107-20-0",
      "pel_ppm": "(C)1",
      "pel_mgm3": "(C)3",
      "id": "chloroacetaldehyde",
      "url": "https://referencesource.org/workplace-exposure-limits/chloroacetaldehyde/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chloroacetaldehyde | 107-20-0 | (C)1 | (C)3 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "(C)1",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Chloroacetaldehyde | 107-20-0 | (C)1 | (C)3 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "107200 | | Chloroacetaldehyde | 1 | 3 | C",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "(C)3",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Chloroacetaldehyde | 107-20-0 | (C)1 | (C)3 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "3",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "107200 | | Chloroacetaldehyde | 1 | 3 | C",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Chloroacetone",
      "pel_ppm": "1",
      "pel_mgm3": "3.8",
      "ceiling": "C",
      "id": "chloroacetone",
      "url": "https://referencesource.org/workplace-exposure-limits/chloroacetone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78955 | S | Chloroacetone | 1 | 3.8 | C"
    },
    {
      "substance": "Chloroacetyl chloride",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.2",
      "stel_ppm": "0.15",
      "stel_mgm3": "0.69",
      "id": "chloroacetyl-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/chloroacetyl-chloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "79049 | S | Chloroacetyl chloride | 0.05 | 0.2 | | 0.15 | 0.69"
    },
    {
      "substance": "Chlorobenzene",
      "cas_number": "108-90-7",
      "pel_ppm": "75",
      "pel_mgm3": "350",
      "id": "chlorobenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorobenzene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chlorobenzene | 108-90-7 | 75 | 350 | - |"
    },
    {
      "substance": "Chlorobenzene; monochlorobenzene",
      "pel_ppm": "10",
      "pel_mgm3": "46",
      "id": "chlorobenzene-monochlorobenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorobenzene-monochlorobenzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108907 | | Chlorobenzene; monochlorobenzene | 10 | 46"
    },
    {
      "substance": "Chlorobromomethane",
      "cas_number": "74-97-5",
      "pel_ppm": "200",
      "pel_mgm3": "1050",
      "id": "chlorobromomethane",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorobromomethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chlorobromomethane | 74-97-5 | 200 | 1050 | - |"
    },
    {
      "substance": "Chlorobromomethane; bromochloromethane",
      "pel_ppm": "200",
      "pel_mgm3": "1,050",
      "id": "chlorobromomethane-bromochloromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorobromomethane-bromochloromethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74975 | | Chlorobromomethane; bromochloromethane | 200 | 1,050"
    },
    {
      "substance": "Chlorodifluoromethane; Fluorocarbon 22",
      "pel_ppm": "1,000",
      "pel_mgm3": "3,500",
      "id": "chlorodifluoromethane-fluorocarbon-22",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorodifluoromethane-fluorocarbon-22/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75456 | | Chlorodifluoromethane; Fluorocarbon 22 | 1,000 | 3,500"
    },
    {
      "substance": "Chlorodiphenyl (42% chlorine)",
      "pel_mgm3": "1",
      "id": "chlorodiphenyl-42-chlorine",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorodiphenyl-42-chlorine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "53469219 | S | Chlorodiphenyl (42% chlorine) | -- | 1"
    },
    {
      "substance": "Chlorodiphenyl (42% Chlorine) (PCB)",
      "cas_number": "53469-21-9",
      "pel_mgm3": "1",
      "id": "chlorodiphenyl-42-chlorine-pcb",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorodiphenyl-42-chlorine-pcb/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chlorodiphenyl (42% Chlorine) (PCB) | 53469-21-9 | - | 1 | X |"
    },
    {
      "substance": "Chlorodiphenyl (54% chlorine)",
      "pel_mgm3": "0.5",
      "id": "chlorodiphenyl-54-chlorine",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorodiphenyl-54-chlorine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "11097691 | S | Chlorodiphenyl (54% chlorine) | -- | 0.5"
    },
    {
      "substance": "Chlorodiphenyl (54% Chlorine) (PCB)",
      "cas_number": "11097-69-1",
      "pel_mgm3": "0.5",
      "id": "chlorodiphenyl-54-chlorine-pcb",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorodiphenyl-54-chlorine-pcb/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chlorodiphenyl (54% Chlorine) (PCB) | 11097-69-1 | - | 0.5 | X |"
    },
    {
      "substance": "Chloroethane; see Ethyl chloride",
      "id": "chloroethane-see-ethyl-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/chloroethane-see-ethyl-chloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75003 | | Chloroethane; see Ethyl chloride"
    },
    {
      "substance": "Chloroethylene, see Vinyl chloride, Section 5210",
      "id": "chloroethylene-see-vinyl-chloride-section-5210",
      "url": "https://referencesource.org/workplace-exposure-limits/chloroethylene-see-vinyl-chloride-section-5210/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75014 | | Chloroethylene, see Vinyl chloride, Section 5210"
    },
    {
      "substance": "Chloroform (Trichloromethane)",
      "cas_number": "67-66-3",
      "pel_ppm": "(C)50",
      "pel_mgm3": "(C)240",
      "id": "chloroform-trichloromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/chloroform-trichloromethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chloroform (Trichloromethane) | 67-66-3 | (C)50 | (C)240 | - |"
    },
    {
      "substance": "Chloroform; trichloromethane",
      "pel_ppm": "2",
      "pel_mgm3": "9.78",
      "id": "chloroform-trichloromethane-2",
      "url": "https://referencesource.org/workplace-exposure-limits/chloroform-trichloromethane-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "67663 | | Chloroform; trichloromethane | 2 | 9.78"
    },
    {
      "substance": "Chloromethane, see Methyl chloride",
      "id": "chloromethane-see-methyl-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/chloromethane-see-methyl-chloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74873 | | Chloromethane, see Methyl chloride"
    },
    {
      "substance": "Chloromethyl methyl ether; see 1910.1006",
      "cas_number": "107-30-2",
      "id": "chloromethyl-methyl-ether-see-1910-1006",
      "url": "https://referencesource.org/workplace-exposure-limits/chloromethyl-methyl-ether-see-1910-1006/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chloromethyl methyl ether; see 1910.1006 | 107-30-2 | - | - | - |"
    },
    {
      "substance": "Chloromethyl methyl ether; see Methyl chloromethyl ether, Section 5209",
      "id": "chloromethyl-methyl-ether-see-methyl-chloromethyl-ether-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/chloromethyl-methyl-ether-see-methyl-chloromethyl-ether-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107302 | | Chloromethyl methyl ether; see Methyl chloromethyl ether, Section 5209"
    },
    {
      "substance": "Chloropentafluoroethane",
      "pel_ppm": "1,000",
      "pel_mgm3": "6,320",
      "id": "chloropentafluoroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/chloropentafluoroethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "76153 | | Chloropentafluoroethane | 1,000 | 6,320"
    },
    {
      "substance": "Chloropicrin",
      "cas_number": "76-06-2",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.7",
      "id": "chloropicrin",
      "url": "https://referencesource.org/workplace-exposure-limits/chloropicrin/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chloropicrin | 76-06-2 | 0.1 | 0.7 | - |"
    },
    {
      "substance": "Chloropicrin; trichloronitromethane",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.7",
      "id": "chloropicrin-trichloronitromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/chloropicrin-trichloronitromethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "76062 | | Chloropicrin; trichloronitromethane | 0.1 | 0.7"
    },
    {
      "substance": "Chloroprene; 2-chloro-1,3-butadiene",
      "pel_ppm": "10",
      "pel_mgm3": "36",
      "id": "chloroprene-2-chloro-1-3-butadiene",
      "url": "https://referencesource.org/workplace-exposure-limits/chloroprene-2-chloro-1-3-butadiene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "126998 | S | Chloroprene; 2-chloro-1,3-butadiene | 10 | 36"
    },
    {
      "substance": "Chlorpyrifos",
      "pel_mgm3": "0.2",
      "id": "chlorpyrifos",
      "url": "https://referencesource.org/workplace-exposure-limits/chlorpyrifos/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "2921882 | S | Chlorpyrifos | -- | 0.2"
    },
    {
      "substance": "Chromium metal",
      "pel_mgm3": "0.5",
      "id": "chromium-metal",
      "url": "https://referencesource.org/workplace-exposure-limits/chromium-metal/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440473 | | Chromium metal | -- | 0.5"
    },
    {
      "substance": "Chromium metal and insol. salts (as Cr)",
      "cas_number": "7440-47-3",
      "pel_mgm3": "1",
      "id": "chromium-metal-and-insol-salts-as-cr",
      "url": "https://referencesource.org/workplace-exposure-limits/chromium-metal-and-insol-salts-as-cr/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Chromium metal and insol. salts (as Cr) | 7440-47-3 | - | 1 | - |"
    },
    {
      "substance": "Chromyl chloride",
      "pel_ppm": "0.025",
      "pel_mgm3": "0.15",
      "id": "chromyl-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/chromyl-chloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "14977618 | | Chromyl chloride | 0.025 | 0.15"
    },
    {
      "substance": "Clopidol",
      "cas_number": "2971-90-6",
      "id": "clopidol",
      "url": "https://referencesource.org/workplace-exposure-limits/clopidol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Clopidol | 2971-90-6 | - | - | - |",
      "disagreements": []
    },
    {
      "substance": "Coal tar pitch volatiles (benzene soluble fraction), anthracene, BaP, phenanthrene, acridine, chrysene, pyrene",
      "cas_number": "65966-93-2",
      "pel_mgm3": "0.2",
      "id": "coal-tar-pitch-volatiles-benzene-soluble-fraction-anthracene-bap-phenanthrene-ac",
      "url": "https://referencesource.org/workplace-exposure-limits/coal-tar-pitch-volatiles-benzene-soluble-fraction-anthracene-bap-phenanthrene-ac/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Coal tar pitch volatiles (benzene soluble fraction), anthracene, BaP, phenanthrene, acridine, chrysene, pyrene | 65966-93-2 | - | 0.2 | - |"
    },
    {
      "substance": "Cobalt hydrocarbonyl, as Co",
      "pel_mgm3": "0.1",
      "id": "cobalt-hydrocarbonyl-as-co",
      "url": "https://referencesource.org/workplace-exposure-limits/cobalt-hydrocarbonyl-as-co/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "16842038 | | Cobalt hydrocarbonyl, as Co | -- | 0.1"
    },
    {
      "substance": "Cobalt metal, dust, and fume (as Co)",
      "cas_number": "7440-48-4",
      "pel_mgm3": "0.1",
      "id": "cobalt-metal-dust-and-fume-as-co",
      "url": "https://referencesource.org/workplace-exposure-limits/cobalt-metal-dust-and-fume-as-co/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Cobalt metal, dust, and fume (as Co) | 7440-48-4 | - | 0.1 | - |"
    },
    {
      "substance": "Cobalt, metal fume and dust, as Co",
      "pel_mgm3": "0.02",
      "id": "cobalt-metal-fume-and-dust-as-co",
      "url": "https://referencesource.org/workplace-exposure-limits/cobalt-metal-fume-and-dust-as-co/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440484 | | Cobalt, metal fume and dust, as Co | -- | 0.02"
    },
    {
      "substance": "Copper",
      "cas_number": "7440-50-8",
      "id": "copper",
      "url": "https://referencesource.org/workplace-exposure-limits/copper/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Copper | 7440-50-8 | - | - | - |"
    },
    {
      "substance": "Copper metal fume, as Cu",
      "pel_mgm3": "0.1",
      "id": "copper-metal-fume-as-cu",
      "url": "https://referencesource.org/workplace-exposure-limits/copper-metal-fume-as-cu/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440508 | | Copper metal fume, as Cu | -- | 0.1"
    },
    {
      "substance": "Crag herbicide (Sesone)",
      "cas_number": "136-78-7",
      "id": "crag-herbicide-sesone",
      "url": "https://referencesource.org/workplace-exposure-limits/crag-herbicide-sesone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Crag herbicide (Sesone) | 136-78-7 | - | - | - |"
    },
    {
      "substance": "Cresol, all isomers",
      "cas_number": "1319-77-3",
      "pel_ppm": "5",
      "pel_mgm3": "22",
      "id": "cresol-all-isomers",
      "url": "https://referencesource.org/workplace-exposure-limits/cresol-all-isomers/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Cresol, all isomers | 1319-77-3 | 5 | 22 | X |"
    },
    {
      "substance": "Cresol (all isomers)",
      "pel_ppm": "5",
      "pel_mgm3": "22",
      "id": "cresol-all-isomers-2",
      "url": "https://referencesource.org/workplace-exposure-limits/cresol-all-isomers-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1319773 | S | Cresol (all isomers) | 5 | 22"
    },
    {
      "substance": "Cristobalite,",
      "pel_mgm3": "0.05",
      "id": "cristobalite",
      "url": "https://referencesource.org/workplace-exposure-limits/cristobalite/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "14464461 | | Cristobalite, | -- | 0.05"
    },
    {
      "substance": "Cristobalite; see 1910.1053 7",
      "cas_number": "14464-46-1",
      "id": "cristobalite-see-1910-1053-7",
      "url": "https://referencesource.org/workplace-exposure-limits/cristobalite-see-1910-1053-7/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Cristobalite; see 1910.1053 7 | 14464-46-1 | - | - | - |"
    },
    {
      "substance": "Crotonaldehyde; beta-methylacrolein",
      "ceiling": "0.3",
      "id": "crotonaldehyde-beta-methylacrolein",
      "url": "https://referencesource.org/workplace-exposure-limits/crotonaldehyde-beta-methylacrolein/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "123739 | S | Crotonaldehyde; beta-methylacrolein | | | 0.3"
    },
    {
      "substance": "Crufomate",
      "pel_mgm3": "5",
      "id": "crufomate",
      "url": "https://referencesource.org/workplace-exposure-limits/crufomate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "299865 | | Crufomate | -- | 5"
    },
    {
      "substance": "Cumene",
      "cas_number": "98-82-8",
      "pel_ppm": "50",
      "pel_mgm3": "245",
      "id": "cumene",
      "url": "https://referencesource.org/workplace-exposure-limits/cumene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Cumene | 98-82-8 | 50 | 245 | X |"
    },
    {
      "substance": "Cumene; isopropylbenzene",
      "pel_ppm": "50",
      "pel_mgm3": "245",
      "id": "cumene-isopropylbenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/cumene-isopropylbenzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "98828 | S | Cumene; isopropylbenzene | 50 | 245"
    },
    {
      "substance": "Cyanamide",
      "pel_mgm3": "2",
      "id": "cyanamide",
      "url": "https://referencesource.org/workplace-exposure-limits/cyanamide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "420042 | | Cyanamide | -- | 2"
    },
    {
      "substance": "Cyanogen",
      "pel_ppm": "10",
      "pel_mgm3": "20",
      "id": "cyanogen",
      "url": "https://referencesource.org/workplace-exposure-limits/cyanogen/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "460195 | | Cyanogen | 10 | 20"
    },
    {
      "substance": "Cyanogen chloride",
      "pel_ppm": "0.3",
      "pel_mgm3": "0.6",
      "ceiling": "C",
      "id": "cyanogen-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/cyanogen-chloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "506774 | | Cyanogen chloride | 0.3 | 0.6 | C"
    },
    {
      "substance": "Cyclohexane",
      "cas_number": "110-82-7",
      "pel_ppm": "300",
      "pel_mgm3": "1050",
      "id": "cyclohexane",
      "url": "https://referencesource.org/workplace-exposure-limits/cyclohexane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Cyclohexane | 110-82-7 | 300 | 1050 | - |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "1050",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Cyclohexane | 110-82-7 | 300 | 1050 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1,050",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "110827 | | Cyclohexane | 300 | 1,050",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Cyclohexanol",
      "cas_number": "108-93-0",
      "pel_ppm": "50",
      "pel_mgm3": "200",
      "id": "cyclohexanol",
      "url": "https://referencesource.org/workplace-exposure-limits/cyclohexanol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Cyclohexanol | 108-93-0 | 50 | 200 | - |",
      "disagreements": []
    },
    {
      "substance": "Cyclohexanone",
      "cas_number": "108-94-1",
      "pel_ppm": "50",
      "pel_mgm3": "200",
      "id": "cyclohexanone",
      "url": "https://referencesource.org/workplace-exposure-limits/cyclohexanone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Cyclohexanone | 108-94-1 | 50 | 200 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "50",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Cyclohexanone | 108-94-1 | 50 | 200 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "25",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "108941 | S | Cyclohexanone | 25 | 100",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "200",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Cyclohexanone | 108-94-1 | 50 | 200 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "100",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "108941 | S | Cyclohexanone | 25 | 100",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Cyclohexene",
      "cas_number": "110-83-8",
      "pel_ppm": "300",
      "pel_mgm3": "1015",
      "id": "cyclohexene",
      "url": "https://referencesource.org/workplace-exposure-limits/cyclohexene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Cyclohexene | 110-83-8 | 300 | 1015 | - |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "1015",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Cyclohexene | 110-83-8 | 300 | 1015 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1,015",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "110838 | | Cyclohexene | 300 | 1,015",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Cyclohexylamine",
      "pel_ppm": "10",
      "pel_mgm3": "40",
      "id": "cyclohexylamine",
      "url": "https://referencesource.org/workplace-exposure-limits/cyclohexylamine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108918 | S | Cyclohexylamine | 10 | 40"
    },
    {
      "substance": "Cyclonite; RDX; cyclotrimethylenetrinitramine",
      "pel_mgm3": "0.07",
      "id": "cyclonite-rdx-cyclotrimethylenetrinitramine",
      "url": "https://referencesource.org/workplace-exposure-limits/cyclonite-rdx-cyclotrimethylenetrinitramine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "121824 | S | Cyclonite; RDX; cyclotrimethylenetrinitramine | -- | 0.07"
    },
    {
      "substance": "Cyclopentadiene",
      "cas_number": "542-92-7",
      "pel_ppm": "75",
      "pel_mgm3": "200",
      "id": "cyclopentadiene",
      "url": "https://referencesource.org/workplace-exposure-limits/cyclopentadiene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Cyclopentadiene | 542-92-7 | 75 | 200 | - |",
      "disagreements": []
    },
    {
      "substance": "Cyclopentane",
      "pel_ppm": "600",
      "pel_mgm3": "1,720",
      "id": "cyclopentane",
      "url": "https://referencesource.org/workplace-exposure-limits/cyclopentane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "287923 | | Cyclopentane | 600 | 1,720"
    },
    {
      "substance": "Cyhexatin; tricyclohexyltin hydroxide",
      "pel_mgm3": "5",
      "id": "cyhexatin-tricyclohexyltin-hydroxide",
      "url": "https://referencesource.org/workplace-exposure-limits/cyhexatin-tricyclohexyltin-hydroxide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "13121705 | | Cyhexatin; tricyclohexyltin hydroxide | | 5"
    },
    {
      "substance": "D-Benzoquinone; see Quinone",
      "id": "d-benzoquinone-see-quinone",
      "url": "https://referencesource.org/workplace-exposure-limits/d-benzoquinone-see-quinone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106514 | | D-Benzoquinone; see Quinone"
    },
    {
      "substance": "DDT; 1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane",
      "pel_mgm3": "1",
      "id": "ddt-1-1-1-trichloro-2-2-bis-p-chlorophenyl-ethane",
      "url": "https://referencesource.org/workplace-exposure-limits/ddt-1-1-1-trichloro-2-2-bis-p-chlorophenyl-ethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "50293 | S | DDT; 1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane | -- | 1"
    },
    {
      "substance": "DDVP, see Dichlorvos",
      "id": "ddvp-see-dichlorvos",
      "url": "https://referencesource.org/workplace-exposure-limits/ddvp-see-dichlorvos/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "62737 | | DDVP, see Dichlorvos"
    },
    {
      "substance": "Decaborane",
      "cas_number": "17702-41-9",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.3",
      "id": "decaborane",
      "url": "https://referencesource.org/workplace-exposure-limits/decaborane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Decaborane | 17702-41-9 | 0.05 | 0.3 | X |",
      "disagreements": []
    },
    {
      "substance": "Demeton; a mixture of o,o-diethyl o-2(ethylthio)ethyl phosphorothloate and o,o'-diethyl S-2(ethylthio)ethyl phosphorothioate",
      "pel_ppm": "0.01",
      "pel_mgm3": "0.1",
      "id": "demeton-a-mixture-of-o-o-diethyl-o-2-ethylthio-ethyl-phosphorothloate-and-o-o-di",
      "url": "https://referencesource.org/workplace-exposure-limits/demeton-a-mixture-of-o-o-diethyl-o-2-ethylthio-ethyl-phosphorothloate-and-o-o-di/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "8065483 | S | Demeton; a mixture of o,o-diethyl o-2(ethylthio)ethyl phosphorothloate and o,o'-diethyl S-2(ethylthio)ethyl phosphorothioate | 0.01 | 0.1"
    },
    {
      "substance": "Demeton (Systox)",
      "cas_number": "8065-48-3",
      "pel_mgm3": "0.1",
      "id": "demeton-systox",
      "url": "https://referencesource.org/workplace-exposure-limits/demeton-systox/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Demeton (Systox) | 8065-48-3 | - | 0.1 | X |"
    },
    {
      "substance": "Di-(2-ethylhexyl) phthalate; see Di-sec-octyl phthalate",
      "id": "di-2-ethylhexyl-phthalate-see-di-sec-octyl-phthalate",
      "url": "https://referencesource.org/workplace-exposure-limits/di-2-ethylhexyl-phthalate-see-di-sec-octyl-phthalate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "117817 | | Di-(2-ethylhexyl) phthalate; see Di-sec-octyl phthalate"
    },
    {
      "substance": "Di-sec-octyl phthalate; bis(2 ethylhexyl) phthalate",
      "pel_mgm3": "5",
      "id": "di-sec-octyl-phthalate-bis-2-ethylhexyl-phthalate",
      "url": "https://referencesource.org/workplace-exposure-limits/di-sec-octyl-phthalate-bis-2-ethylhexyl-phthalate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "117817 | | Di-sec-octyl phthalate; bis(2 ethylhexyl) phthalate | -- | 5 | | --"
    },
    {
      "substance": "Di-sec octyl phthalate (Di-(2-ethylhexyl) phthalate)",
      "cas_number": "117-81-7",
      "pel_mgm3": "5",
      "id": "di-sec-octyl-phthalate-di-2-ethylhexyl-phthalate",
      "url": "https://referencesource.org/workplace-exposure-limits/di-sec-octyl-phthalate-di-2-ethylhexyl-phthalate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Di-sec octyl phthalate (Di-(2-ethylhexyl) phthalate) | 117-81-7 | - | 5 | - |"
    },
    {
      "substance": "Diacetone alcohol (4-Hydroxy-4-methyl-2-pentanone)",
      "cas_number": "123-42-2",
      "pel_ppm": "50",
      "pel_mgm3": "240",
      "id": "diacetone-alcohol-4-hydroxy-4-methyl-2-pentanone",
      "url": "https://referencesource.org/workplace-exposure-limits/diacetone-alcohol-4-hydroxy-4-methyl-2-pentanone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Diacetone alcohol (4-Hydroxy-4-methyl-2-pentanone) | 123-42-2 | 50 | 240 | - |"
    },
    {
      "substance": "Diacetone alcohol; 4-hydroxy-4-methyl-2-pentanone",
      "pel_ppm": "50",
      "pel_mgm3": "240",
      "id": "diacetone-alcohol-4-hydroxy-4-methyl-2-pentanone-2",
      "url": "https://referencesource.org/workplace-exposure-limits/diacetone-alcohol-4-hydroxy-4-methyl-2-pentanone-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "123422 | | Diacetone alcohol; 4-hydroxy-4-methyl-2-pentanone | 50 | 240"
    },
    {
      "substance": "Diazinon; o,o-diethyl o-(2-isopropyl-6-methyl-4-pyrimidinyl) phosphorothioate",
      "pel_mgm3": "0.1",
      "id": "diazinon-o-o-diethyl-o-2-isopropyl-6-methyl-4-pyrimidinyl-phosphorothioate",
      "url": "https://referencesource.org/workplace-exposure-limits/diazinon-o-o-diethyl-o-2-isopropyl-6-methyl-4-pyrimidinyl-phosphorothioate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "333415 | S | Diazinon; o,o-diethyl o-(2-isopropyl-6-methyl-4-pyrimidinyl) phosphorothioate | -- | 0.1"
    },
    {
      "substance": "Diazomethane",
      "cas_number": "334-88-3",
      "pel_ppm": "0.2",
      "pel_mgm3": "0.4",
      "id": "diazomethane",
      "url": "https://referencesource.org/workplace-exposure-limits/diazomethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Diazomethane | 334-88-3 | 0.2 | 0.4 | - |",
      "disagreements": []
    },
    {
      "substance": "Dibenzoyl peroxide; see Benzoyl peroxide",
      "id": "dibenzoyl-peroxide-see-benzoyl-peroxide",
      "url": "https://referencesource.org/workplace-exposure-limits/dibenzoyl-peroxide-see-benzoyl-peroxide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "94360 | | Dibenzoyl peroxide; see Benzoyl peroxide"
    },
    {
      "substance": "Diborane",
      "cas_number": "19287-45-7",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.1",
      "id": "diborane",
      "url": "https://referencesource.org/workplace-exposure-limits/diborane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Diborane | 19287-45-7 | 0.1 | 0.1 | - |",
      "disagreements": []
    },
    {
      "substance": "Dibromodifluoromethane; see Difluorodibromomethane",
      "id": "dibromodifluoromethane-see-difluorodibromomethane",
      "url": "https://referencesource.org/workplace-exposure-limits/dibromodifluoromethane-see-difluorodibromomethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75616 | | Dibromodifluoromethane; see Difluorodibromomethane"
    },
    {
      "substance": "Dibutyl phenyl phosphate",
      "pel_ppm": "0.3",
      "pel_mgm3": "3.5",
      "id": "dibutyl-phenyl-phosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/dibutyl-phenyl-phosphate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "2528361 | S | Dibutyl phenyl phosphate | 0.3 | 3.5"
    },
    {
      "substance": "Dibutyl phosphate",
      "cas_number": "107-66-4",
      "pel_ppm": "1",
      "pel_mgm3": "5",
      "id": "dibutyl-phosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/dibutyl-phosphate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dibutyl phosphate | 107-66-4 | 1 | 5 | - |",
      "disagreements": []
    },
    {
      "substance": "Dibutyl phthalate",
      "cas_number": "84-74-2",
      "pel_mgm3": "5",
      "id": "dibutyl-phthalate",
      "url": "https://referencesource.org/workplace-exposure-limits/dibutyl-phthalate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dibutyl phthalate | 84-74-2 | - | 5 | - |",
      "disagreements": []
    },
    {
      "substance": "Dichloroacetylene",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.4",
      "ceiling": "C",
      "id": "dichloroacetylene",
      "url": "https://referencesource.org/workplace-exposure-limits/dichloroacetylene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7572294 | | Dichloroacetylene | 0.1 | 0.4 | C"
    },
    {
      "substance": "Dichlorodifluoromethane",
      "cas_number": "75-71-8",
      "pel_ppm": "1000",
      "pel_mgm3": "4950",
      "id": "dichlorodifluoromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/dichlorodifluoromethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dichlorodifluoromethane | 75-71-8 | 1000 | 4950 | - |",
      "disagreements": []
    },
    {
      "substance": "Dichlorodiphenyltrichloroethane (DDT)",
      "cas_number": "50-29-3",
      "pel_mgm3": "1",
      "id": "dichlorodiphenyltrichloroethane-ddt",
      "url": "https://referencesource.org/workplace-exposure-limits/dichlorodiphenyltrichloroethane-ddt/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dichlorodiphenyltrichloroethane (DDT) | 50-29-3 | - | 1 | X |"
    },
    {
      "substance": "Dichloroethyl ether",
      "cas_number": "111-44-4",
      "pel_ppm": "(C)15",
      "pel_mgm3": "(C)90",
      "id": "dichloroethyl-ether",
      "url": "https://referencesource.org/workplace-exposure-limits/dichloroethyl-ether/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dichloroethyl ether | 111-44-4 | (C)15 | (C)90 | X |"
    },
    {
      "substance": "Dichloroethyl ether; bis(2-chloroethyl) ether",
      "pel_ppm": "5",
      "pel_mgm3": "30",
      "stel_ppm": "10",
      "stel_mgm3": "60",
      "id": "dichloroethyl-ether-bis-2-chloroethyl-ether",
      "url": "https://referencesource.org/workplace-exposure-limits/dichloroethyl-ether-bis-2-chloroethyl-ether/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "111444 | S | Dichloroethyl ether; bis(2-chloroethyl) ether | 5 | 30 | | 10 | 60"
    },
    {
      "substance": "Dichlorofluoromethane; Fluorocarbon 21",
      "pel_ppm": "10",
      "pel_mgm3": "42",
      "id": "dichlorofluoromethane-fluorocarbon-21",
      "url": "https://referencesource.org/workplace-exposure-limits/dichlorofluoromethane-fluorocarbon-21/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75434 | | Dichlorofluoromethane; Fluorocarbon 21 | 10 | 42"
    },
    {
      "substance": "Dichloromethane; see Methylene chloride",
      "id": "dichloromethane-see-methylene-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/dichloromethane-see-methylene-chloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75092 | | Dichloromethane; see Methylene chloride"
    },
    {
      "substance": "Dichloromonofluoromethane",
      "cas_number": "75-43-4",
      "pel_ppm": "1000",
      "pel_mgm3": "4200",
      "id": "dichloromonofluoromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/dichloromonofluoromethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dichloromonofluoromethane | 75-43-4 | 1000 | 4200 | - |"
    },
    {
      "substance": "Dichloropropene",
      "pel_ppm": "1",
      "pel_mgm3": "5",
      "id": "dichloropropene",
      "url": "https://referencesource.org/workplace-exposure-limits/dichloropropene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "542756 | S | Dichloropropene | 1 | 5"
    },
    {
      "substance": "Dichlorotetrafluoroethane",
      "cas_number": "76-14-2",
      "pel_ppm": "1000",
      "pel_mgm3": "7000",
      "id": "dichlorotetrafluoroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/dichlorotetrafluoroethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dichlorotetrafluoroethane | 76-14-2 | 1000 | 7000 | - |"
    },
    {
      "substance": "Dichlorvos (DDVP)",
      "cas_number": "62-73-7",
      "pel_mgm3": "1",
      "id": "dichlorvos-ddvp",
      "url": "https://referencesource.org/workplace-exposure-limits/dichlorvos-ddvp/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dichlorvos (DDVP) | 62-73-7 | - | 1 | X |"
    },
    {
      "substance": "Dichlorvos (DDVP); 2,2-dichlorovinyl dimethyl phosphate",
      "pel_ppm": "0.1",
      "pel_mgm3": "1",
      "id": "dichlorvos-ddvp-2-2-dichlorovinyl-dimethyl-phosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/dichlorvos-ddvp-2-2-dichlorovinyl-dimethyl-phosphate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "62737 | S | Dichlorvos (DDVP); 2,2-dichlorovinyl dimethyl phosphate | 0.1 | 1"
    },
    {
      "substance": "Dicrotophos",
      "pel_mgm3": "0.25",
      "id": "dicrotophos",
      "url": "https://referencesource.org/workplace-exposure-limits/dicrotophos/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "141662 | S | Dicrotophos | -- | 0.25"
    },
    {
      "substance": "Dicyclohexylmethane-4,4'-diisocyanate; see Methylene bis-(4-cyclohexylisocyanate)",
      "id": "dicyclohexylmethane-4-4-diisocyanate-see-methylene-bis-4-cyclohexylisocyanate",
      "url": "https://referencesource.org/workplace-exposure-limits/dicyclohexylmethane-4-4-diisocyanate-see-methylene-bis-4-cyclohexylisocyanate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "5124301 | | Dicyclohexylmethane-4,4'-diisocyanate; see Methylene bis-(4-cyclohexylisocyanate)"
    },
    {
      "substance": "Dicyclopentadiene",
      "pel_ppm": "5",
      "pel_mgm3": "30",
      "id": "dicyclopentadiene",
      "url": "https://referencesource.org/workplace-exposure-limits/dicyclopentadiene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "77736 | | Dicyclopentadiene | 5 | 30"
    },
    {
      "substance": "Dicyclopentadienyl iron",
      "cas_number": "102-54-5",
      "id": "dicyclopentadienyl-iron",
      "url": "https://referencesource.org/workplace-exposure-limits/dicyclopentadienyl-iron/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dicyclopentadienyl iron | 102-54-5 | - | - | - |",
      "disagreements": []
    },
    {
      "substance": "Dieldrin",
      "cas_number": "60-57-1",
      "pel_mgm3": "0.25",
      "id": "dieldrin",
      "url": "https://referencesource.org/workplace-exposure-limits/dieldrin/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dieldrin | 60-57-1 | - | 0.25 | X |"
    },
    {
      "substance": "Dieldrin; 1,2,3,4,10,10-hexachloro-6,7-epoxy-1,4,4a,5,6,7,8,8a-octahydro-1,4-endo-exo-5,8-dimethanonaphthalene",
      "pel_mgm3": "0.25",
      "id": "dieldrin-1-2-3-4-10-10-hexachloro-6-7-epoxy-1-4-4a-5-6-7-8-8a-octahydro-1-4-endo",
      "url": "https://referencesource.org/workplace-exposure-limits/dieldrin-1-2-3-4-10-10-hexachloro-6-7-epoxy-1-4-4a-5-6-7-8-8a-octahydro-1-4-endo/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "60571 | S | Dieldrin; 1,2,3,4,10,10-hexachloro-6,7-epoxy-1,4,4a,5,6,7,8,8a-octahydro-1,4-endo-exo-5,8-dimethanonaphthalene | -- | 0.25"
    },
    {
      "substance": "Diethanolamine",
      "pel_ppm": "0.46",
      "pel_mgm3": "2",
      "id": "diethanolamine",
      "url": "https://referencesource.org/workplace-exposure-limits/diethanolamine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "111422 | S | Diethanolamine | 0.46 | 2"
    },
    {
      "substance": "Diethyl ether; see Ethyl ether",
      "id": "diethyl-ether-see-ethyl-ether",
      "url": "https://referencesource.org/workplace-exposure-limits/diethyl-ether-see-ethyl-ether/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "60297 | | Diethyl ether; see Ethyl ether"
    },
    {
      "substance": "Diethyl ketone",
      "pel_ppm": "200",
      "pel_mgm3": "705",
      "stel_ppm": "300",
      "stel_mgm3": "1057",
      "id": "diethyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/diethyl-ketone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "96220 | | Diethyl ketone | 200 | 705 | | 300 | 1057"
    },
    {
      "substance": "Diethyl phthalate",
      "pel_mgm3": "5",
      "id": "diethyl-phthalate",
      "url": "https://referencesource.org/workplace-exposure-limits/diethyl-phthalate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "84662 | | Diethyl phthalate | -- | 5"
    },
    {
      "substance": "Diethylamine",
      "cas_number": "109-89-7",
      "pel_ppm": "25",
      "pel_mgm3": "75",
      "id": "diethylamine",
      "url": "https://referencesource.org/workplace-exposure-limits/diethylamine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Diethylamine | 109-89-7 | 25 | 75 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "25",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Diethylamine | 109-89-7 | 25 | 75 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "109897 | S | Diethylamine | 5 | 15 | C",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "75",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Diethylamine | 109-89-7 | 25 | 75 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "15",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "109897 | S | Diethylamine | 5 | 15 | C",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Diethylene glycol diethyl ether, Ethyl diglyme",
      "pel_ppm": "5",
      "pel_mgm3": "33",
      "id": "diethylene-glycol-diethyl-ether-ethyl-diglyme",
      "url": "https://referencesource.org/workplace-exposure-limits/diethylene-glycol-diethyl-ether-ethyl-diglyme/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "112367 | S | Diethylene glycol diethyl ether, Ethyl diglyme | 5 | 33"
    },
    {
      "substance": "Diethylene glycol dimethyl ether, Diglyme",
      "pel_ppm": "1",
      "pel_mgm3": "5.5",
      "stel_ppm": "5",
      "stel_mgm3": "27",
      "id": "diethylene-glycol-dimethyl-ether-diglyme",
      "url": "https://referencesource.org/workplace-exposure-limits/diethylene-glycol-dimethyl-ether-diglyme/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "111966 | S | Diethylene glycol dimethyl ether, Diglyme | 1 | 5.5 | | 5 | 27"
    },
    {
      "substance": "Difluorodibromomethane",
      "cas_number": "75-61-6",
      "pel_ppm": "100",
      "pel_mgm3": "860",
      "id": "difluorodibromomethane",
      "url": "https://referencesource.org/workplace-exposure-limits/difluorodibromomethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Difluorodibromomethane | 75-61-6 | 100 | 860 | - |"
    },
    {
      "substance": "Difluorodibromomethane; dibromodifluoromethane",
      "pel_ppm": "100",
      "pel_mgm3": "860",
      "id": "difluorodibromomethane-dibromodifluoromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/difluorodibromomethane-dibromodifluoromethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75616 | | Difluorodibromomethane; dibromodifluoromethane | 100 | 860"
    },
    {
      "substance": "Diglycidyl ether (DGE)",
      "cas_number": "2238-07-5",
      "pel_ppm": "(C)0.5",
      "pel_mgm3": "(C)2.8",
      "id": "diglycidyl-ether-dge",
      "url": "https://referencesource.org/workplace-exposure-limits/diglycidyl-ether-dge/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Diglycidyl ether (DGE) | 2238-07-5 | (C)0.5 | (C)2.8 | - |"
    },
    {
      "substance": "Diglycidyl ether; DGE; bis(2,3-epoxypropyl) ether",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.5",
      "id": "diglycidyl-ether-dge-bis-2-3-epoxypropyl-ether",
      "url": "https://referencesource.org/workplace-exposure-limits/diglycidyl-ether-dge-bis-2-3-epoxypropyl-ether/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "2238075 | | Diglycidyl ether; DGE; bis(2,3-epoxypropyl) ether | 0.1 | 0.5"
    },
    {
      "substance": "Diisobutyl ketone",
      "cas_number": "108-83-8",
      "pel_ppm": "50",
      "pel_mgm3": "290",
      "id": "diisobutyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/diisobutyl-ketone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Diisobutyl ketone | 108-83-8 | 50 | 290 | - |"
    },
    {
      "substance": "Diisobutyl ketone; 2,6-dimethyl-4-heptanone",
      "pel_ppm": "25",
      "pel_mgm3": "150",
      "id": "diisobutyl-ketone-2-6-dimethyl-4-heptanone",
      "url": "https://referencesource.org/workplace-exposure-limits/diisobutyl-ketone-2-6-dimethyl-4-heptanone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108838 | | Diisobutyl ketone; 2,6-dimethyl-4-heptanone | 25 | 150"
    },
    {
      "substance": "Diisopropyl ether; see Isopryl ether",
      "id": "diisopropyl-ether-see-isopryl-ether",
      "url": "https://referencesource.org/workplace-exposure-limits/diisopropyl-ether-see-isopryl-ether/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108203 | | Diisopropyl ether; see Isopryl ether"
    },
    {
      "substance": "Diisopropylamine",
      "cas_number": "108-18-9",
      "pel_ppm": "5",
      "pel_mgm3": "20",
      "id": "diisopropylamine",
      "url": "https://referencesource.org/workplace-exposure-limits/diisopropylamine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Diisopropylamine | 108-18-9 | 5 | 20 | X |",
      "disagreements": []
    },
    {
      "substance": "Dimethoxymethane; see Methylal",
      "id": "dimethoxymethane-see-methylal",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethoxymethane-see-methylal/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "109875 | | Dimethoxymethane; see Methylal"
    },
    {
      "substance": "Dimethyl-1,2-dibromo-2,2-dichloroethyl phosphate",
      "cas_number": "300-76-5",
      "pel_mgm3": "3",
      "id": "dimethyl-1-2-dibromo-2-2-dichloroethyl-phosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethyl-1-2-dibromo-2-2-dichloroethyl-phosphate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dimethyl-1,2-dibromo-2,2-dichloroethyl phosphate | 300-76-5 | - | 3 | - |"
    },
    {
      "substance": "Dimethyl acetamide",
      "cas_number": "127-19-5",
      "pel_ppm": "10",
      "pel_mgm3": "35",
      "id": "dimethyl-acetamide",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethyl-acetamide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dimethyl acetamide | 127-19-5 | 10 | 35 | X |"
    },
    {
      "substance": "Dimethyl ketone; see Acetone",
      "id": "dimethyl-ketone-see-acetone",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethyl-ketone-see-acetone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "67641 | | Dimethyl ketone; see Acetone"
    },
    {
      "substance": "Dimethyl phthalate",
      "pel_mgm3": "5",
      "id": "dimethyl-phthalate",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethyl-phthalate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "131113 | | Dimethyl phthalate | -- | 5"
    },
    {
      "substance": "Dimethyl sulfate",
      "cas_number": "77-78-1",
      "pel_ppm": "1",
      "pel_mgm3": "5",
      "id": "dimethyl-sulfate",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethyl-sulfate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dimethyl sulfate | 77-78-1 | 1 | 5 | X |"
    },
    {
      "substance": "Dimethyl sulfate; methyl sulfate",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.5",
      "id": "dimethyl-sulfate-methyl-sulfate",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethyl-sulfate-methyl-sulfate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "77781 | S | Dimethyl sulfate; methyl sulfate | 0.1 | 0.5"
    },
    {
      "substance": "Dimethylacetamide",
      "pel_ppm": "10",
      "pel_mgm3": "35",
      "id": "dimethylacetamide",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethylacetamide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "127195 | S | Dimethylacetamide | 10 | 35"
    },
    {
      "substance": "Dimethylamine",
      "cas_number": "124-40-3",
      "pel_ppm": "10",
      "pel_mgm3": "18",
      "id": "dimethylamine",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethylamine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dimethylamine | 124-40-3 | 10 | 18 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "10",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Dimethylamine | 124-40-3 | 10 | 18 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "124403 | | Dimethylamine | 5 | 9.2 | | 15 | 27.6",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "18",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Dimethylamine | 124-40-3 | 10 | 18 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "9.2",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "124403 | | Dimethylamine | 5 | 9.2 | | 15 | 27.6",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Dimethylaminobenzene; see Xylidene",
      "id": "dimethylaminobenzene-see-xylidene",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethylaminobenzene-see-xylidene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1300738 | | Dimethylaminobenzene; see Xylidene"
    },
    {
      "substance": "Dimethylaniline (N,N-Dimethylaniline)",
      "cas_number": "121-69-7",
      "pel_ppm": "5",
      "pel_mgm3": "25",
      "id": "dimethylaniline-n-n-dimethylaniline",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethylaniline-n-n-dimethylaniline/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dimethylaniline (N,N-Dimethylaniline) | 121-69-7 | 5 | 25 | X |"
    },
    {
      "substance": "Dimethylbenzene; see Xylene",
      "id": "dimethylbenzene-see-xylene",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethylbenzene-see-xylene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1330207 | | Dimethylbenzene; see Xylene"
    },
    {
      "substance": "Dimethylethoxysilane",
      "pel_ppm": "0.5",
      "pel_mgm3": "2.1",
      "stel_ppm": "1.5",
      "stel_mgm3": "6.4",
      "id": "dimethylethoxysilane",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethylethoxysilane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "14857342 | | Dimethylethoxysilane | 0.5 | 2.1 | | 1.5 | 6.4"
    },
    {
      "substance": "Dimethylformamide",
      "cas_number": "68-12-2",
      "pel_ppm": "10",
      "pel_mgm3": "30",
      "id": "dimethylformamide",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethylformamide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dimethylformamide | 68-12-2 | 10 | 30 | X |"
    },
    {
      "substance": "Dimethylformamide; DMF",
      "pel_ppm": "10",
      "pel_mgm3": "30",
      "id": "dimethylformamide-dmf",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethylformamide-dmf/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "68122 | S | Dimethylformamide; DMF | 10 | 30"
    },
    {
      "substance": "Dimethylphthalate",
      "cas_number": "131-11-3",
      "pel_mgm3": "5",
      "id": "dimethylphthalate",
      "url": "https://referencesource.org/workplace-exposure-limits/dimethylphthalate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dimethylphthalate | 131-11-3 | - | 5 | - |"
    },
    {
      "substance": "Dinitolmide; 3,5-Dinitro-o-toluamide",
      "pel_mgm3": "5",
      "id": "dinitolmide-3-5-dinitro-o-toluamide",
      "url": "https://referencesource.org/workplace-exposure-limits/dinitolmide-3-5-dinitro-o-toluamide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "148016 | | Dinitolmide; 3,5-Dinitro-o-toluamide | -- | 5"
    },
    {
      "substance": "Dinitro-o-cresol",
      "cas_number": "534-52-1",
      "pel_mgm3": "0.2",
      "id": "dinitro-o-cresol",
      "url": "https://referencesource.org/workplace-exposure-limits/dinitro-o-cresol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dinitro-o-cresol | 534-52-1 | - | 0.2 | X |"
    },
    {
      "substance": "Dinitrotoluene",
      "cas_number": "25321-14-6",
      "pel_mgm3": "1.5",
      "id": "dinitrotoluene",
      "url": "https://referencesource.org/workplace-exposure-limits/dinitrotoluene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dinitrotoluene | 25321-14-6 | - | 1.5 | X |"
    },
    {
      "substance": "Dioxane (Diethylene dioxide)",
      "cas_number": "123-91-1",
      "pel_ppm": "100",
      "pel_mgm3": "360",
      "id": "dioxane-diethylene-dioxide",
      "url": "https://referencesource.org/workplace-exposure-limits/dioxane-diethylene-dioxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dioxane (Diethylene dioxide) | 123-91-1 | 100 | 360 | X |"
    },
    {
      "substance": "Dioxathion",
      "pel_mgm3": "0.2",
      "id": "dioxathion",
      "url": "https://referencesource.org/workplace-exposure-limits/dioxathion/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78342 | S | Dioxathion | -- | 0.2"
    },
    {
      "substance": "Diphenyl (Biphenyl)",
      "cas_number": "92-52-4",
      "pel_ppm": "0.2",
      "pel_mgm3": "1",
      "id": "diphenyl-biphenyl",
      "url": "https://referencesource.org/workplace-exposure-limits/diphenyl-biphenyl/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Diphenyl (Biphenyl) | 92-52-4 | 0.2 | 1 | - |"
    },
    {
      "substance": "Diphenyl; see Biphenyl",
      "id": "diphenyl-see-biphenyl",
      "url": "https://referencesource.org/workplace-exposure-limits/diphenyl-see-biphenyl/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "92524 | | Diphenyl; see Biphenyl"
    },
    {
      "substance": "Diphenylamine; N-phenylaniline",
      "pel_mgm3": "10",
      "id": "diphenylamine-n-phenylaniline",
      "url": "https://referencesource.org/workplace-exposure-limits/diphenylamine-n-phenylaniline/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "122394 | | Diphenylamine; N-phenylaniline | -- | 10"
    },
    {
      "substance": "Diphenylmethane diisocyanate; see Methylene bis(phenylisocyanate)",
      "id": "diphenylmethane-diisocyanate-see-methylene-bis-phenylisocyanate",
      "url": "https://referencesource.org/workplace-exposure-limits/diphenylmethane-diisocyanate-see-methylene-bis-phenylisocyanate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "101688 | | Diphenylmethane diisocyanate; see Methylene bis(phenylisocyanate)"
    },
    {
      "substance": "Dipropyl ketone",
      "pel_ppm": "50",
      "pel_mgm3": "235",
      "id": "dipropyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/dipropyl-ketone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "123193 | | Dipropyl ketone | 50 | 235"
    },
    {
      "substance": "Dipropylene glycol methyl ether",
      "cas_number": "34590-94-8",
      "pel_ppm": "100",
      "pel_mgm3": "600",
      "id": "dipropylene-glycol-methyl-ether",
      "url": "https://referencesource.org/workplace-exposure-limits/dipropylene-glycol-methyl-ether/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Dipropylene glycol methyl ether | 34590-94-8 | 100 | 600 | X |",
      "disagreements": []
    },
    {
      "substance": "Diquat; 1,1'-ethylene-2,2'-dipyridinium dibromide",
      "id": "diquat-1-1-ethylene-2-2-dipyridinium-dibromide",
      "url": "https://referencesource.org/workplace-exposure-limits/diquat-1-1-ethylene-2-2-dipyridinium-dibromide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "85007 | | Diquat; 1,1'-ethylene-2,2'-dipyridinium dibromide | --"
    },
    {
      "substance": "Disulfiram",
      "pel_mgm3": "2",
      "id": "disulfiram",
      "url": "https://referencesource.org/workplace-exposure-limits/disulfiram/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "97778 | | Disulfiram | -- | 2"
    },
    {
      "substance": "Disulfoton; o,o-diethyl S-2-(ethylthio)ethyl phosphorodithioate",
      "pel_mgm3": "0.1",
      "id": "disulfoton-o-o-diethyl-s-2-ethylthio-ethyl-phosphorodithioate",
      "url": "https://referencesource.org/workplace-exposure-limits/disulfoton-o-o-diethyl-s-2-ethylthio-ethyl-phosphorodithioate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "298044 | S | Disulfoton; o,o-diethyl S-2-(ethylthio)ethyl phosphorodithioate | -- | 0.1"
    },
    {
      "substance": "Diuron",
      "pel_mgm3": "10",
      "id": "diuron",
      "url": "https://referencesource.org/workplace-exposure-limits/diuron/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "330541 | | Diuron | -- | 10"
    },
    {
      "substance": "Divinyl benzene",
      "pel_ppm": "10",
      "pel_mgm3": "50",
      "id": "divinyl-benzene",
      "url": "https://referencesource.org/workplace-exposure-limits/divinyl-benzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1321740 | | Divinyl benzene | 10 | 50"
    },
    {
      "substance": "DMF; see Dimethylformamide",
      "id": "dmf-see-dimethylformamide",
      "url": "https://referencesource.org/workplace-exposure-limits/dmf-see-dimethylformamide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "68122 | | DMF; see Dimethylformamide"
    },
    {
      "substance": "DMH; see 1,1-Dimethylhydrazine",
      "id": "dmh-see-1-1-dimethylhydrazine",
      "url": "https://referencesource.org/workplace-exposure-limits/dmh-see-1-1-dimethylhydrazine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "57147 | | DMH; see 1,1-Dimethylhydrazine"
    },
    {
      "substance": "Emery",
      "cas_number": "12415-34-8",
      "id": "emery",
      "url": "https://referencesource.org/workplace-exposure-limits/emery/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Emery | 12415-34-8 | - | - | - |"
    },
    {
      "substance": "Emery; see Particulates not otherwise regulated",
      "id": "emery-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/emery-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "12415348 | | Emery; see Particulates not otherwise regulated"
    },
    {
      "substance": "Endosulfan; 6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4, 3-benzodioxathiepin-3-oxide",
      "pel_mgm3": "0.1",
      "id": "endosulfan-6-7-8-9-10-10-hexachloro-1-5-5a-6-9-9a-hexahydro-6-9-methano-2-4-3-be",
      "url": "https://referencesource.org/workplace-exposure-limits/endosulfan-6-7-8-9-10-10-hexachloro-1-5-5a-6-9-9a-hexahydro-6-9-methano-2-4-3-be/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "115297 | S | Endosulfan; 6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4, 3-benzodioxathiepin-3-oxide | -- | 0.1"
    },
    {
      "substance": "Endrin",
      "cas_number": "72-20-8",
      "pel_mgm3": "0.1",
      "id": "endrin",
      "url": "https://referencesource.org/workplace-exposure-limits/endrin/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Endrin | 72-20-8 | - | 0.1 | X |"
    },
    {
      "substance": "Endrin; 1,2,3,4,10,10-hexachloro-6,7-epoxy-1,4,4a,5,6,7,8,8a-octahydro-1,4-endo-endo-5, 8-dimethanonaphthalene",
      "pel_mgm3": "0.1",
      "id": "endrin-1-2-3-4-10-10-hexachloro-6-7-epoxy-1-4-4a-5-6-7-8-8a-octahydro-1-4-endo-e",
      "url": "https://referencesource.org/workplace-exposure-limits/endrin-1-2-3-4-10-10-hexachloro-6-7-epoxy-1-4-4a-5-6-7-8-8a-octahydro-1-4-endo-e/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "72208 | S | Endrin; 1,2,3,4,10,10-hexachloro-6,7-epoxy-1,4,4a,5,6,7,8,8a-octahydro-1,4-endo-endo-5, 8-dimethanonaphthalene | -- | 0.1"
    },
    {
      "substance": "Enflurane",
      "pel_ppm": "2",
      "pel_mgm3": "15",
      "id": "enflurane",
      "url": "https://referencesource.org/workplace-exposure-limits/enflurane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "13838169 | | Enflurane | 2 | 15"
    },
    {
      "substance": "Epichlorohydrin",
      "cas_number": "106-89-8",
      "pel_ppm": "5",
      "pel_mgm3": "19",
      "id": "epichlorohydrin",
      "url": "https://referencesource.org/workplace-exposure-limits/epichlorohydrin/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Epichlorohydrin | 106-89-8 | 5 | 19 | X |"
    },
    {
      "substance": "Epichlorohydrin; 1-chloro-2, 3-epoxypropane",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.19",
      "id": "epichlorohydrin-1-chloro-2-3-epoxypropane",
      "url": "https://referencesource.org/workplace-exposure-limits/epichlorohydrin-1-chloro-2-3-epoxypropane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106898 | S | Epichlorohydrin; 1-chloro-2, 3-epoxypropane | 0.05 | 0.19"
    },
    {
      "substance": "EPN",
      "cas_number": "2104-64-5",
      "pel_mgm3": "0.5",
      "id": "epn",
      "url": "https://referencesource.org/workplace-exposure-limits/epn/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "EPN | 2104-64-5 | - | 0.5 | X |"
    },
    {
      "substance": "EPN; o-ethyl o-(p-nitrophenyl) phenylphosphonothioate",
      "pel_mgm3": "0.1",
      "id": "epn-o-ethyl-o-p-nitrophenyl-phenylphosphonothioate",
      "url": "https://referencesource.org/workplace-exposure-limits/epn-o-ethyl-o-p-nitrophenyl-phenylphosphonothioate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "2104645 | S | EPN; o-ethyl o-(p-nitrophenyl) phenylphosphonothioate | -- | 0.1"
    },
    {
      "substance": "Ethane",
      "id": "ethane",
      "url": "https://referencesource.org/workplace-exposure-limits/ethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74840 | | Ethane | (h) | --"
    },
    {
      "substance": "Ethanethiol; see Ethyl mercaptan",
      "id": "ethanethiol-see-ethyl-mercaptan",
      "url": "https://referencesource.org/workplace-exposure-limits/ethanethiol-see-ethyl-mercaptan/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75081 | | Ethanethiol; see Ethyl mercaptan"
    },
    {
      "substance": "Ethanol; see Ethyl alcohol",
      "id": "ethanol-see-ethyl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/ethanol-see-ethyl-alcohol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "64175 | | Ethanol; see Ethyl alcohol"
    },
    {
      "substance": "Ethanolamine",
      "cas_number": "141-43-5",
      "pel_ppm": "3",
      "pel_mgm3": "6",
      "id": "ethanolamine",
      "url": "https://referencesource.org/workplace-exposure-limits/ethanolamine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethanolamine | 141-43-5 | 3 | 6 | - |"
    },
    {
      "substance": "Ethanolamine; 2-aminoethanol",
      "pel_ppm": "3",
      "pel_mgm3": "8",
      "stel_ppm": "6",
      "stel_mgm3": "15",
      "id": "ethanolamine-2-aminoethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/ethanolamine-2-aminoethanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "141435 | | Ethanolamine; 2-aminoethanol | 3 | 8 | | 6 | 15"
    },
    {
      "substance": "Ethion",
      "pel_mgm3": "0.4",
      "id": "ethion",
      "url": "https://referencesource.org/workplace-exposure-limits/ethion/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "563122 | S | Ethion | -- | 0.4"
    },
    {
      "substance": "Ethyl acetate",
      "cas_number": "141-78-6",
      "pel_ppm": "400",
      "pel_mgm3": "1400",
      "id": "ethyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethyl acetate | 141-78-6 | 400 | 1400 | - |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "1400",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Ethyl acetate | 141-78-6 | 400 | 1400 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1,400",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "141786 | | Ethyl acetate | 400 | 1,400",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Ethyl acrylate",
      "cas_number": "140-88-5",
      "pel_ppm": "25",
      "pel_mgm3": "100",
      "id": "ethyl-acrylate",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-acrylate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethyl acrylate | 140-88-5 | 25 | 100 | X |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "25",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Ethyl acrylate | 140-88-5 | 25 | 100 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "140885 | S | Ethyl acrylate | 5 | 20 | | 25 | 100",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "100",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Ethyl acrylate | 140-88-5 | 25 | 100 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "20",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "140885 | S | Ethyl acrylate | 5 | 20 | | 25 | 100",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Ethyl alcohol (Ethanol)",
      "cas_number": "64-17-5",
      "pel_ppm": "1000",
      "pel_mgm3": "1900",
      "id": "ethyl-alcohol-ethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-alcohol-ethanol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethyl alcohol (Ethanol) | 64-17-5 | 1000 | 1900 | - |"
    },
    {
      "substance": "Ethyl alcohol; ethanol",
      "pel_ppm": "1,000",
      "pel_mgm3": "1,900",
      "id": "ethyl-alcohol-ethanol-2",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-alcohol-ethanol-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "64175 | | Ethyl alcohol; ethanol | 1,000 | 1,900"
    },
    {
      "substance": "Ethyl amyl ketone (5-Methyl-3-heptanone)",
      "cas_number": "541-85-5",
      "pel_ppm": "25",
      "pel_mgm3": "130",
      "id": "ethyl-amyl-ketone-5-methyl-3-heptanone",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-amyl-ketone-5-methyl-3-heptanone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethyl amyl ketone (5-Methyl-3-heptanone) | 541-85-5 | 25 | 130 | - |"
    },
    {
      "substance": "Ethyl benzene",
      "cas_number": "100-41-4",
      "pel_ppm": "100",
      "pel_mgm3": "435",
      "id": "ethyl-benzene",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-benzene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethyl benzene | 100-41-4 | 100 | 435 | - |"
    },
    {
      "substance": "Ethyl bromide",
      "cas_number": "74-96-4",
      "pel_ppm": "200",
      "pel_mgm3": "890",
      "id": "ethyl-bromide",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-bromide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethyl bromide | 74-96-4 | 200 | 890 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "200",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Ethyl bromide | 74-96-4 | 200 | 890 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "74964 | S | Ethyl bromide | 5 | 22",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "890",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Ethyl bromide | 74-96-4 | 200 | 890 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "22",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "74964 | S | Ethyl bromide | 5 | 22",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Ethyl butyl ketone (3-Heptanone)",
      "cas_number": "106-35-4",
      "pel_ppm": "50",
      "pel_mgm3": "230",
      "id": "ethyl-butyl-ketone-3-heptanone",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-butyl-ketone-3-heptanone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethyl butyl ketone (3-Heptanone) | 106-35-4 | 50 | 230 | - |"
    },
    {
      "substance": "Ethyl butyl ketone; 3-heptanone",
      "pel_ppm": "50",
      "pel_mgm3": "230",
      "stel_ppm": "75",
      "stel_mgm3": "345",
      "id": "ethyl-butyl-ketone-3-heptanone-2",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-butyl-ketone-3-heptanone-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106354 | | Ethyl butyl ketone; 3-heptanone | 50 | 230 | | 75 | 345"
    },
    {
      "substance": "Ethyl chloride",
      "cas_number": "75-00-3",
      "pel_ppm": "1000",
      "pel_mgm3": "2600",
      "id": "ethyl-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-chloride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethyl chloride | 75-00-3 | 1000 | 2600 | - |"
    },
    {
      "substance": "Ethyl chloride; chloroethane",
      "pel_ppm": "100",
      "pel_mgm3": "264",
      "id": "ethyl-chloride-chloroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-chloride-chloroethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75003 | S | Ethyl chloride; chloroethane | 100 | 264"
    },
    {
      "substance": "Ethyl cyanoacrylate",
      "pel_ppm": "0.2",
      "pel_mgm3": "1.02",
      "id": "ethyl-cyanoacrylate",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-cyanoacrylate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7085850 | | Ethyl cyanoacrylate | 0.2 | 1.02"
    },
    {
      "substance": "Ethyl ether",
      "cas_number": "60-29-7",
      "pel_ppm": "400",
      "pel_mgm3": "1200",
      "id": "ethyl-ether",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-ether/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethyl ether | 60-29-7 | 400 | 1200 | - |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "1200",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Ethyl ether | 60-29-7 | 400 | 1200 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1,200",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "60297 | | Ethyl ether | 400 | 1,200 | | 500 | 1500",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Ethyl formate",
      "cas_number": "109-94-4",
      "pel_ppm": "100",
      "pel_mgm3": "300",
      "id": "ethyl-formate",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-formate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethyl formate | 109-94-4 | 100 | 300 | - |",
      "disagreements": []
    },
    {
      "substance": "Ethyl mercaptan",
      "cas_number": "75-08-1",
      "pel_ppm": "(C)10",
      "pel_mgm3": "(C)25",
      "id": "ethyl-mercaptan",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-mercaptan/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethyl mercaptan | 75-08-1 | (C)10 | (C)25 | - |"
    },
    {
      "substance": "Ethyl mercaptan; ethanethiol",
      "pel_ppm": "0.5",
      "pel_mgm3": "1",
      "id": "ethyl-mercaptan-ethanethiol",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-mercaptan-ethanethiol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75081 | | Ethyl mercaptan; ethanethiol | 0.5 | 1"
    },
    {
      "substance": "Ethyl methyl ketone; see Methyl ethyl ketone",
      "id": "ethyl-methyl-ketone-see-methyl-ethyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-methyl-ketone-see-methyl-ethyl-ketone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78933 | | Ethyl methyl ketone; see Methyl ethyl ketone"
    },
    {
      "substance": "Ethyl sec-amyl ketone; 5-methyl-3-heptanone",
      "pel_ppm": "25",
      "pel_mgm3": "130",
      "id": "ethyl-sec-amyl-ketone-5-methyl-3-heptanone",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-sec-amyl-ketone-5-methyl-3-heptanone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "541855 | | Ethyl sec-amyl ketone; 5-methyl-3-heptanone | 25 | 130"
    },
    {
      "substance": "Ethyl silicate",
      "cas_number": "78-10-4",
      "pel_ppm": "100",
      "pel_mgm3": "850",
      "id": "ethyl-silicate",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-silicate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethyl silicate | 78-10-4 | 100 | 850 | - |"
    },
    {
      "substance": "Ethyl silicate; tetraethyl silicate",
      "pel_ppm": "10",
      "pel_mgm3": "85",
      "id": "ethyl-silicate-tetraethyl-silicate",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-silicate-tetraethyl-silicate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78104 | | Ethyl silicate; tetraethyl silicate | 10 | 85"
    },
    {
      "substance": "Ethyl tert-butyl ether",
      "pel_ppm": "5",
      "pel_mgm3": "21",
      "id": "ethyl-tert-butyl-ether",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyl-tert-butyl-ether/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "637923 | | Ethyl tert-butyl ether | 5 | 21"
    },
    {
      "substance": "Ethylamine",
      "cas_number": "75-04-7",
      "pel_ppm": "10",
      "pel_mgm3": "18",
      "id": "ethylamine",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylamine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethylamine | 75-04-7 | 10 | 18 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "10",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Ethylamine | 75-04-7 | 10 | 18 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "75047 | S | Ethylamine | 5 | 9.2 | C",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "18",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Ethylamine | 75-04-7 | 10 | 18 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "9.2",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "75047 | S | Ethylamine | 5 | 9.2 | C",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Ethylbenzene",
      "pel_ppm": "5",
      "pel_mgm3": "22",
      "stel_ppm": "30",
      "stel_mgm3": "130",
      "id": "ethylbenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylbenzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "100414 | | Ethylbenzene | 5 | 22 | | 30 | 130"
    },
    {
      "substance": "Ethylene",
      "id": "ethylene",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74851 | | Ethylene | (h) | --"
    },
    {
      "substance": "Ethylene chlorohydrin",
      "cas_number": "107-07-3",
      "pel_ppm": "5",
      "pel_mgm3": "16",
      "id": "ethylene-chlorohydrin",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-chlorohydrin/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethylene chlorohydrin | 107-07-3 | 5 | 16 | X |"
    },
    {
      "substance": "Ethylene chlorohydrin; 2-chloroethanol",
      "pel_ppm": "1",
      "pel_mgm3": "3",
      "ceiling": "C",
      "id": "ethylene-chlorohydrin-2-chloroethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-chlorohydrin-2-chloroethanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107073 | S | Ethylene chlorohydrin; 2-chloroethanol | 1 | 3 | C"
    },
    {
      "substance": "Ethylene dibromide",
      "cas_number": "106-93-4",
      "id": "ethylene-dibromide",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-dibromide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethylene dibromide | 106-93-4 | - | ( 2 ) | - |"
    },
    {
      "substance": "Ethylene dibromide; 1,2-dibromoethane, see Section 5219",
      "pel_ppm": "0.13",
      "pel_mgm3": "1",
      "ceiling": "C",
      "id": "ethylene-dibromide-1-2-dibromoethane-see-section-5219",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-dibromide-1-2-dibromoethane-see-section-5219/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106934 | S | Ethylene dibromide; 1,2-dibromoethane, see Section 5219 | 0.13 | 1 | C"
    },
    {
      "substance": "Ethylene dichloride (1,2-Dichloroethane)",
      "cas_number": "107-06-2",
      "id": "ethylene-dichloride-1-2-dichloroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-dichloride-1-2-dichloroethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethylene dichloride (1,2-Dichloroethane) | 107-06-2 | - | ( 2 ) | - |"
    },
    {
      "substance": "Ethylene dichloride; 1,2-dichloroethane",
      "pel_ppm": "1",
      "pel_mgm3": "4",
      "ceiling": "200 ppm",
      "stel_ppm": "2",
      "stel_mgm3": "8",
      "id": "ethylene-dichloride-1-2-dichloroethane-2",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-dichloride-1-2-dichloroethane-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107062 | | Ethylene dichloride; 1,2-dichloroethane | 1 | 4 | 200 ppm | 2 | 8"
    },
    {
      "substance": "Ethylene glycol diethyl ether, 1,2-diethoxyethane",
      "pel_ppm": "5",
      "pel_mgm3": "24",
      "id": "ethylene-glycol-diethyl-ether-1-2-diethoxyethane",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-glycol-diethyl-ether-1-2-diethoxyethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "629141 | S | Ethylene glycol diethyl ether, 1,2-diethoxyethane | 5 | 24"
    },
    {
      "substance": "Ethylene glycol dimethyl ether, 1,2-dimethoxyethane, Glyme",
      "pel_ppm": "1",
      "pel_mgm3": "3.7",
      "stel_ppm": "5",
      "stel_mgm3": "18",
      "id": "ethylene-glycol-dimethyl-ether-1-2-dimethoxyethane-glyme",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-glycol-dimethyl-ether-1-2-dimethoxyethane-glyme/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "110714 | S | Ethylene glycol dimethyl ether, 1,2-dimethoxyethane, Glyme | 1 | 3.7 | | 5 | 18"
    },
    {
      "substance": "Ethylene glycol dinitrate",
      "cas_number": "628-96-6",
      "pel_ppm": "(C)0.2",
      "pel_mgm3": "(C)1",
      "id": "ethylene-glycol-dinitrate",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-glycol-dinitrate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethylene glycol dinitrate | 628-96-6 | (C)0.2 | (C)1 | X |",
      "disagreements": []
    },
    {
      "substance": "Ethylene glycol monoethyl ether, see 2-Ethoxyethanol",
      "id": "ethylene-glycol-monoethyl-ether-see-2-ethoxyethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-glycol-monoethyl-ether-see-2-ethoxyethanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "110805 | S | Ethylene glycol monoethyl ether, see 2-Ethoxyethanol"
    },
    {
      "substance": "Ethylene glycol monomethyl ether acetate; see 2-Methoxyethyl acetate",
      "id": "ethylene-glycol-monomethyl-ether-acetate-see-2-methoxyethyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-glycol-monomethyl-ether-acetate-see-2-methoxyethyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "110496 | S | Ethylene glycol monomethyl ether acetate; see 2-Methoxyethyl acetate"
    },
    {
      "substance": "Ethylene glycol monomethyl ether, see 2-Methoxyethanol",
      "id": "ethylene-glycol-monomethyl-ether-see-2-methoxyethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-glycol-monomethyl-ether-see-2-methoxyethanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "109864 | S | Ethylene glycol monomethyl ether, see 2-Methoxyethanol"
    },
    {
      "substance": "Ethylene glycol (vapor)",
      "pel_ppm": "40",
      "pel_mgm3": "100",
      "ceiling": "C",
      "id": "ethylene-glycol-vapor",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-glycol-vapor/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107211 | | Ethylene glycol (vapor) | 40 | 100 | C"
    },
    {
      "substance": "Ethylene oxide; see 1910.1047",
      "cas_number": "75-21-8",
      "id": "ethylene-oxide-see-1910-1047",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-oxide-see-1910-1047/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethylene oxide; see 1910.1047 | 75-21-8 | - | - | - |"
    },
    {
      "substance": "Ethylene oxide; see Section 5220",
      "pel_ppm": "1",
      "pel_mgm3": "2",
      "stel_ppm": "5",
      "id": "ethylene-oxide-see-section-5220",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylene-oxide-see-section-5220/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75218 | | Ethylene oxide; see Section 5220 | 1 | 2 | | 5"
    },
    {
      "substance": "Ethylenediamine",
      "cas_number": "107-15-3",
      "pel_ppm": "10",
      "pel_mgm3": "25",
      "id": "ethylenediamine",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylenediamine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethylenediamine | 107-15-3 | 10 | 25 | - |"
    },
    {
      "substance": "Ethylenediamine; 1,2-diaminoethane",
      "pel_ppm": "10",
      "pel_mgm3": "25",
      "id": "ethylenediamine-1-2-diaminoethane",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylenediamine-1-2-diaminoethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107153 | | Ethylenediamine; 1,2-diaminoethane | 10 | 25"
    },
    {
      "substance": "Ethyleneimine; see 1910.1012",
      "cas_number": "151-56-4",
      "id": "ethyleneimine-see-1910-1012",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyleneimine-see-1910-1012/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ethyleneimine; see 1910.1012 | 151-56-4 | - | - | - |"
    },
    {
      "substance": "Ethyleneimine; see also Section 5209",
      "pel_ppm": "0.5",
      "pel_mgm3": "1",
      "id": "ethyleneimine-see-also-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/ethyleneimine-see-also-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "151564 | S | Ethyleneimine; see also Section 5209 | 0.5 | 1"
    },
    {
      "substance": "Ethylidene chloride; see 1,1-Dichloroethane",
      "id": "ethylidene-chloride-see-1-1-dichloroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylidene-chloride-see-1-1-dichloroethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75343 | | Ethylidene chloride; see 1,1-Dichloroethane"
    },
    {
      "substance": "Ethylidene norbornene",
      "pel_ppm": "5",
      "pel_mgm3": "25",
      "ceiling": "C",
      "id": "ethylidene-norbornene",
      "url": "https://referencesource.org/workplace-exposure-limits/ethylidene-norbornene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "16219753 | | Ethylidene norbornene | 5 | 25 | C"
    },
    {
      "substance": "Fenamiphos",
      "pel_mgm3": "0.1",
      "id": "fenamiphos",
      "url": "https://referencesource.org/workplace-exposure-limits/fenamiphos/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "22224926 | S | Fenamiphos | | 0.1"
    },
    {
      "substance": "Fensulfothion",
      "pel_mgm3": "0.1",
      "id": "fensulfothion",
      "url": "https://referencesource.org/workplace-exposure-limits/fensulfothion/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "115902 | | Fensulfothion | -- | 0.1"
    },
    {
      "substance": "Fenthion",
      "pel_mgm3": "0.2",
      "id": "fenthion",
      "url": "https://referencesource.org/workplace-exposure-limits/fenthion/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "55389 | S | Fenthion | -- | 0.2"
    },
    {
      "substance": "Ferbam",
      "cas_number": "14484-64-1",
      "id": "ferbam",
      "url": "https://referencesource.org/workplace-exposure-limits/ferbam/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ferbam | 14484-64-1 | - | - | - |"
    },
    {
      "substance": "Ferbam; ferric N,N-dimethylthiocarbamate",
      "pel_mgm3": "10",
      "id": "ferbam-ferric-n-n-dimethylthiocarbamate",
      "url": "https://referencesource.org/workplace-exposure-limits/ferbam-ferric-n-n-dimethylthiocarbamate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "14484641 | | Ferbam; ferric N,N-dimethylthiocarbamate | -- | 10"
    },
    {
      "substance": "Ferrovanadium dust",
      "cas_number": "12604-58-9",
      "pel_mgm3": "1",
      "id": "ferrovanadium-dust",
      "url": "https://referencesource.org/workplace-exposure-limits/ferrovanadium-dust/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ferrovanadium dust | 12604-58-9 | - | 1 | - |",
      "disagreements": []
    },
    {
      "substance": "Fibrous glass, see Glass",
      "id": "fibrous-glass-see-glass",
      "url": "https://referencesource.org/workplace-exposure-limits/fibrous-glass-see-glass/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "14808607 | | Fibrous glass, see Glass"
    },
    {
      "substance": "Fluorine",
      "cas_number": "7782-41-4",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.2",
      "id": "fluorine",
      "url": "https://referencesource.org/workplace-exposure-limits/fluorine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Fluorine | 7782-41-4 | 0.1 | 0.2 | - |",
      "disagreements": []
    },
    {
      "substance": "Fluorocarbon 11; see Trichlorofluoromethane",
      "id": "fluorocarbon-11-see-trichlorofluoromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/fluorocarbon-11-see-trichlorofluoromethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75694 | | Fluorocarbon 11; see Trichlorofluoromethane"
    },
    {
      "substance": "Fluorocarbon 112; see 1,1,2,2-Tetrachloro-1,2-difluoroethane",
      "id": "fluorocarbon-112-see-1-1-2-2-tetrachloro-1-2-difluoroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/fluorocarbon-112-see-1-1-2-2-tetrachloro-1-2-difluoroethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "76120 | | Fluorocarbon 112; see 1,1,2,2-Tetrachloro-1,2-difluoroethane"
    },
    {
      "substance": "Fluorocarbon 113; see 1,1,2-Trichloro-1,2,2-trifluoroethane",
      "id": "fluorocarbon-113-see-1-1-2-trichloro-1-2-2-trifluoroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/fluorocarbon-113-see-1-1-2-trichloro-1-2-2-trifluoroethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "76131 | | Fluorocarbon 113; see 1,1,2-Trichloro-1,2,2-trifluoroethane"
    },
    {
      "substance": "Fluorocarbon 12; see Dichlorodifluoromethane",
      "id": "fluorocarbon-12-see-dichlorodifluoromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/fluorocarbon-12-see-dichlorodifluoromethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75718 | | Fluorocarbon 12; see Dichlorodifluoromethane"
    },
    {
      "substance": "Fluorocarbon 21; see Dichlorofluoromethane",
      "id": "fluorocarbon-21-see-dichlorofluoromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/fluorocarbon-21-see-dichlorofluoromethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75434 | | Fluorocarbon 21; see Dichlorofluoromethane"
    },
    {
      "substance": "Fluorocarbon 22; see Chlorodifluoromethane",
      "id": "fluorocarbon-22-see-chlorodifluoromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/fluorocarbon-22-see-chlorodifluoromethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75456 | | Fluorocarbon 22; see Chlorodifluoromethane"
    },
    {
      "substance": "Fluorotrichloromethane; see Trichlorofluoromethane",
      "id": "fluorotrichloromethane-see-trichlorofluoromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/fluorotrichloromethane-see-trichlorofluoromethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75694 | | Fluorotrichloromethane; see Trichlorofluoromethane"
    },
    {
      "substance": "Fluorotrichloromethane (Trichlorofluoromethane)",
      "cas_number": "75-69-4",
      "pel_ppm": "1000",
      "pel_mgm3": "5600",
      "id": "fluorotrichloromethane-trichlorofluoromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/fluorotrichloromethane-trichlorofluoromethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Fluorotrichloromethane (Trichlorofluoromethane) | 75-69-4 | 1000 | 5600 | - |"
    },
    {
      "substance": "Fonofos",
      "pel_mgm3": "0.1",
      "id": "fonofos",
      "url": "https://referencesource.org/workplace-exposure-limits/fonofos/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "944229 | S | Fonofos | -- | 0.1"
    },
    {
      "substance": "Formaldehyde; see 1910.1048",
      "cas_number": "50-00-0",
      "id": "formaldehyde-see-1910-1048",
      "url": "https://referencesource.org/workplace-exposure-limits/formaldehyde-see-1910-1048/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Formaldehyde; see 1910.1048 | 50-00-0 | - | - | - |"
    },
    {
      "substance": "Formaldehyde, see Section 5217",
      "pel_ppm": "0.75",
      "stel_ppm": "2",
      "id": "formaldehyde-see-section-5217",
      "url": "https://referencesource.org/workplace-exposure-limits/formaldehyde-see-section-5217/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "50000 | | Formaldehyde, see Section 5217 | 0.75 | -- | | 2 | --"
    },
    {
      "substance": "Formamide",
      "pel_ppm": "10",
      "pel_mgm3": "18",
      "id": "formamide",
      "url": "https://referencesource.org/workplace-exposure-limits/formamide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75127 | S | Formamide | 10 | 18"
    },
    {
      "substance": "Formic acid",
      "cas_number": "64-18-6",
      "pel_ppm": "5",
      "pel_mgm3": "9",
      "id": "formic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/formic-acid/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Formic acid | 64-18-6 | 5 | 9 | - |",
      "disagreements": []
    },
    {
      "substance": "Furfural",
      "cas_number": "98-01-1",
      "pel_ppm": "5",
      "pel_mgm3": "20",
      "id": "furfural",
      "url": "https://referencesource.org/workplace-exposure-limits/furfural/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Furfural | 98-01-1 | 5 | 20 | X |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "5",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Furfural | 98-01-1 | 5 | 20 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "2",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "98011 | S | Furfural | 2 | 8",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "20",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Furfural | 98-01-1 | 5 | 20 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "8",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "98011 | S | Furfural | 2 | 8",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Furfuryl alcohol",
      "cas_number": "98-00-0",
      "pel_ppm": "50",
      "pel_mgm3": "200",
      "id": "furfuryl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/furfuryl-alcohol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Furfuryl alcohol | 98-00-0 | 50 | 200 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "50",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Furfuryl alcohol | 98-00-0 | 50 | 200 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "10",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "98000 | S | Furfuryl alcohol | 10 | 40 | | 15 | 60",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "200",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Furfuryl alcohol | 98-00-0 | 50 | 200 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "40",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "98000 | S | Furfuryl alcohol | 10 | 40 | | 15 | 60",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Gasoline",
      "pel_ppm": "300",
      "pel_mgm3": "900",
      "stel_ppm": "500",
      "stel_mgm3": "1500",
      "id": "gasoline",
      "url": "https://referencesource.org/workplace-exposure-limits/gasoline/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "8006619 | | Gasoline | 300 | 900 | | 500 | 1500"
    },
    {
      "substance": "Germanium tetrahydride",
      "pel_ppm": "0.2",
      "pel_mgm3": "0.6",
      "id": "germanium-tetrahydride",
      "url": "https://referencesource.org/workplace-exposure-limits/germanium-tetrahydride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7782652 | | Germanium tetrahydride | 0.2 | 0.6"
    },
    {
      "substance": "Glutaraldehyde (t)",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.2",
      "ceiling": "C",
      "id": "glutaraldehyde-t",
      "url": "https://referencesource.org/workplace-exposure-limits/glutaraldehyde-t/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "111308 | | Glutaraldehyde (t) | 0.05 | 0.2 | C"
    },
    {
      "substance": "Glycerin (mist)",
      "cas_number": "56-81-5",
      "id": "glycerin-mist",
      "url": "https://referencesource.org/workplace-exposure-limits/glycerin-mist/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Glycerin (mist) | 56-81-5 | - | - | - |"
    },
    {
      "substance": "Glycerin mist; see Particulates not otherwise regulated",
      "id": "glycerin-mist-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/glycerin-mist-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "56815 | | Glycerin mist; see Particulates not otherwise regulated"
    },
    {
      "substance": "Glyceryl stearate",
      "pel_mgm3": "10",
      "id": "glyceryl-stearate",
      "url": "https://referencesource.org/workplace-exposure-limits/glyceryl-stearate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "123944 | | Glyceryl stearate | -- | 10"
    },
    {
      "substance": "Glycidol",
      "cas_number": "556-52-5",
      "pel_ppm": "50",
      "pel_mgm3": "150",
      "id": "glycidol",
      "url": "https://referencesource.org/workplace-exposure-limits/glycidol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Glycidol | 556-52-5 | 50 | 150 | - |"
    },
    {
      "substance": "Glycidol; 2,3-epoxy-1-propanol",
      "pel_ppm": "2",
      "pel_mgm3": "6.1",
      "id": "glycidol-2-3-epoxy-1-propanol",
      "url": "https://referencesource.org/workplace-exposure-limits/glycidol-2-3-epoxy-1-propanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "556525 | | Glycidol; 2,3-epoxy-1-propanol | 2 | 6.1"
    },
    {
      "substance": "Glycol monobutyl ether; see 2-Butoxyethanol",
      "id": "glycol-monobutyl-ether-see-2-butoxyethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/glycol-monobutyl-ether-see-2-butoxyethanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "111762 | | Glycol monobutyl ether; see 2-Butoxyethanol"
    },
    {
      "substance": "Glycol monoethyl ether; see 2-Ethoxyethanol",
      "id": "glycol-monoethyl-ether-see-2-ethoxyethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/glycol-monoethyl-ether-see-2-ethoxyethanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "110805 | | Glycol monoethyl ether; see 2-Ethoxyethanol"
    },
    {
      "substance": "Glycol monomethyl ether; see 2-Methoxyethanol",
      "id": "glycol-monomethyl-ether-see-2-methoxyethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/glycol-monomethyl-ether-see-2-methoxyethanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "109864 | | Glycol monomethyl ether; see 2-Methoxyethanol"
    },
    {
      "substance": "Glyoxal, 1,2-ethanedione",
      "pel_mgm3": "0.1 (s), (u)",
      "id": "glyoxal-1-2-ethanedione",
      "url": "https://referencesource.org/workplace-exposure-limits/glyoxal-1-2-ethanedione/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107222 | | Glyoxal, 1,2-ethanedione | -- | 0.1 (s), (u)"
    },
    {
      "substance": "Graphite, natural, respirable dust",
      "cas_number": "7782-42-5",
      "id": "graphite-natural-respirable-dust",
      "url": "https://referencesource.org/workplace-exposure-limits/graphite-natural-respirable-dust/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Graphite, natural, respirable dust | 7782-42-5 | - | ( 3 ) | - |"
    },
    {
      "substance": "Graphite, natural respirable dust",
      "pel_mgm3": "2.5",
      "id": "graphite-natural-respirable-dust-2",
      "url": "https://referencesource.org/workplace-exposure-limits/graphite-natural-respirable-dust-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7782425 | | Graphite, natural respirable dust | | 2.5"
    },
    {
      "substance": "Gypsum",
      "cas_number": "13397-24-5",
      "id": "gypsum",
      "url": "https://referencesource.org/workplace-exposure-limits/gypsum/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Gypsum | 13397-24-5 | - | - | - |"
    },
    {
      "substance": "Gypsum; Calcium sulfate dihydrate; see Particulates not otherwise regulated",
      "id": "gypsum-calcium-sulfate-dihydrate-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/gypsum-calcium-sulfate-dihydrate-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "13397245 | | Gypsum; Calcium sulfate dihydrate; see Particulates not otherwise regulated"
    },
    {
      "substance": "Hafnium",
      "cas_number": "7440-58-6",
      "pel_mgm3": "0.5",
      "id": "hafnium",
      "url": "https://referencesource.org/workplace-exposure-limits/hafnium/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Hafnium | 7440-58-6 | - | 0.5 | - |",
      "disagreements": []
    },
    {
      "substance": "Halothane",
      "pel_ppm": "2",
      "pel_mgm3": "16",
      "id": "halothane",
      "url": "https://referencesource.org/workplace-exposure-limits/halothane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "151677 | | Halothane | 2 | 16"
    },
    {
      "substance": "HDI; see Hexamethylene diisocyanate",
      "id": "hdi-see-hexamethylene-diisocyanate",
      "url": "https://referencesource.org/workplace-exposure-limits/hdi-see-hexamethylene-diisocyanate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "822060 | | HDI; see Hexamethylene diisocyanate"
    },
    {
      "substance": "Helium",
      "id": "helium",
      "url": "https://referencesource.org/workplace-exposure-limits/helium/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440597 | | Helium | (h) | --"
    },
    {
      "substance": "Heptachlor",
      "cas_number": "76-44-8",
      "pel_mgm3": "0.5",
      "id": "heptachlor",
      "url": "https://referencesource.org/workplace-exposure-limits/heptachlor/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Heptachlor | 76-44-8 | - | 0.5 | X |"
    },
    {
      "substance": "Heptachlor; 1,4,5,6,7,8,8-hepta-chloro-3a,4,7,7a-tetrahydro-4,7-methanoindene",
      "pel_mgm3": "0.05",
      "id": "heptachlor-1-4-5-6-7-8-8-hepta-chloro-3a-4-7-7a-tetrahydro-4-7-methanoindene",
      "url": "https://referencesource.org/workplace-exposure-limits/heptachlor-1-4-5-6-7-8-8-hepta-chloro-3a-4-7-7a-tetrahydro-4-7-methanoindene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "76448 | S | Heptachlor; 1,4,5,6,7,8,8-hepta-chloro-3a,4,7,7a-tetrahydro-4,7-methanoindene | -- | 0.05"
    },
    {
      "substance": "Heptane (n-Heptane)",
      "cas_number": "142-82-5",
      "pel_ppm": "500",
      "pel_mgm3": "2000",
      "id": "heptane-n-heptane",
      "url": "https://referencesource.org/workplace-exposure-limits/heptane-n-heptane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Heptane (n-Heptane) | 142-82-5 | 500 | 2000 | - |"
    },
    {
      "substance": "Hexachlorobenzene",
      "pel_mgm3": "0.002",
      "id": "hexachlorobenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/hexachlorobenzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "118741 | S | Hexachlorobenzene | -- | 0.002"
    },
    {
      "substance": "Hexachlorobutadiene",
      "pel_ppm": "0.02",
      "pel_mgm3": "0.24",
      "id": "hexachlorobutadiene",
      "url": "https://referencesource.org/workplace-exposure-limits/hexachlorobutadiene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "87683 | S | Hexachlorobutadiene | 0.02 | 0.24"
    },
    {
      "substance": "Hexachlorocyclopentadiene",
      "pel_ppm": "0.01",
      "pel_mgm3": "0.11",
      "id": "hexachlorocyclopentadiene",
      "url": "https://referencesource.org/workplace-exposure-limits/hexachlorocyclopentadiene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "77474 | | Hexachlorocyclopentadiene | 0.01 | 0.11"
    },
    {
      "substance": "Hexachloroethane",
      "cas_number": "67-72-1",
      "pel_ppm": "1",
      "pel_mgm3": "10",
      "id": "hexachloroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/hexachloroethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Hexachloroethane | 67-72-1 | 1 | 10 | X |"
    },
    {
      "substance": "Hexachloroethane; perchloroethane",
      "pel_ppm": "1",
      "pel_mgm3": "10",
      "id": "hexachloroethane-perchloroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/hexachloroethane-perchloroethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "67721 | S | Hexachloroethane; perchloroethane | 1 | 10"
    },
    {
      "substance": "Hexachloronaphthalene",
      "cas_number": "1335-87-1",
      "pel_mgm3": "0.2",
      "id": "hexachloronaphthalene",
      "url": "https://referencesource.org/workplace-exposure-limits/hexachloronaphthalene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Hexachloronaphthalene | 1335-87-1 | - | 0.2 | X |",
      "disagreements": []
    },
    {
      "substance": "Hexafluoroacetone; 1,1,1,3,3,3-hexafluoro-2-propanone",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.7",
      "id": "hexafluoroacetone-1-1-1-3-3-3-hexafluoro-2-propanone",
      "url": "https://referencesource.org/workplace-exposure-limits/hexafluoroacetone-1-1-1-3-3-3-hexafluoro-2-propanone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "684162 | S | Hexafluoroacetone; 1,1,1,3,3,3-hexafluoro-2-propanone | 0.1 | 0.7"
    },
    {
      "substance": "Hexamethylene diisocyanate; HDI",
      "pel_ppm": "0.005",
      "pel_mgm3": "0.034",
      "id": "hexamethylene-diisocyanate-hdi",
      "url": "https://referencesource.org/workplace-exposure-limits/hexamethylene-diisocyanate-hdi/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "822060 | | Hexamethylene diisocyanate; HDI | 0.005 | 0.034"
    },
    {
      "substance": "Hexone (Methyl isobutyl ketone)",
      "cas_number": "108-10-1",
      "pel_ppm": "100",
      "pel_mgm3": "410",
      "id": "hexone-methyl-isobutyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/hexone-methyl-isobutyl-ketone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Hexone (Methyl isobutyl ketone) | 108-10-1 | 100 | 410 | - |"
    },
    {
      "substance": "Hexone; see Methyl isobutyl ketone",
      "id": "hexone-see-methyl-isobutyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/hexone-see-methyl-isobutyl-ketone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108101 | | Hexone; see Methyl isobutyl ketone"
    },
    {
      "substance": "Hexylene glycol",
      "pel_ppm": "25",
      "pel_mgm3": "125",
      "ceiling": "C",
      "id": "hexylene-glycol",
      "url": "https://referencesource.org/workplace-exposure-limits/hexylene-glycol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107415 | | Hexylene glycol | 25 | 125 | C"
    },
    {
      "substance": "Hydrazine",
      "cas_number": "302-01-2",
      "pel_ppm": "1",
      "pel_mgm3": "1.3",
      "id": "hydrazine",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrazine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Hydrazine | 302-01-2 | 1 | 1.3 | X |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "1",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Hydrazine | 302-01-2 | 1 | 1.3 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.01",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "302012 | S | Hydrazine | 0.01 | 0.013",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "1.3",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Hydrazine | 302-01-2 | 1 | 1.3 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.013",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "302012 | S | Hydrazine | 0.01 | 0.013",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Hydrobromic acid; see Hydrogen bromide",
      "id": "hydrobromic-acid-see-hydrogen-bromide",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrobromic-acid-see-hydrogen-bromide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "10035106 | | Hydrobromic acid; see Hydrogen bromide"
    },
    {
      "substance": "Hydrochloric acid; see Hydrogen chloride",
      "id": "hydrochloric-acid-see-hydrogen-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrochloric-acid-see-hydrogen-chloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7647010 | | Hydrochloric acid; see Hydrogen chloride"
    },
    {
      "substance": "Hydrocyanic acid; see Hydrogen cyanide",
      "id": "hydrocyanic-acid-see-hydrogen-cyanide",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrocyanic-acid-see-hydrogen-cyanide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74908 | | Hydrocyanic acid; see Hydrogen cyanide"
    },
    {
      "substance": "Hydrofluoric acid; see Hydrogen fluoride",
      "id": "hydrofluoric-acid-see-hydrogen-fluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrofluoric-acid-see-hydrogen-fluoride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7664393 | | Hydrofluoric acid; see Hydrogen fluoride"
    },
    {
      "substance": "Hydrogen",
      "id": "hydrogen",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrogen/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1333740 | | Hydrogen | (h) | --"
    },
    {
      "substance": "Hydrogen bromide",
      "cas_number": "10035-10-6",
      "pel_ppm": "3",
      "pel_mgm3": "10",
      "id": "hydrogen-bromide",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrogen-bromide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Hydrogen bromide | 10035-10-6 | 3 | 10 | - |",
      "disagreements": []
    },
    {
      "substance": "Hydrogen chloride",
      "cas_number": "7647-01-0",
      "pel_ppm": "(C)5",
      "pel_mgm3": "(C)7",
      "id": "hydrogen-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrogen-chloride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Hydrogen chloride | 7647-01-0 | (C)5 | (C)7 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "(C)5",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Hydrogen chloride | 7647-01-0 | (C)5 | (C)7 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.3",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7647010 | | Hydrogen chloride | 0.3 | 0.45 | 2 ppm",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "(C)7",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Hydrogen chloride | 7647-01-0 | (C)5 | (C)7 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.45",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7647010 | | Hydrogen chloride | 0.3 | 0.45 | 2 ppm",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Hydrogen cyanide",
      "cas_number": "74-90-8",
      "pel_ppm": "10",
      "pel_mgm3": "11",
      "id": "hydrogen-cyanide",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrogen-cyanide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Hydrogen cyanide | 74-90-8 | 10 | 11 | X |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "10",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Hydrogen cyanide | 74-90-8 | 10 | 11 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "4.7",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "74908 | S | Hydrogen cyanide | 4.7 | 5 | C",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "11",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Hydrogen cyanide | 74-90-8 | 10 | 11 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "74908 | S | Hydrogen cyanide | 4.7 | 5 | C",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Hydrogen fluoride (as F)",
      "cas_number": "7664-39-3",
      "id": "hydrogen-fluoride-as-f",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrogen-fluoride-as-f/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Hydrogen fluoride (as F) | 7664-39-3 | - | ( 2 ) | - |"
    },
    {
      "substance": "Hydrogen fluoride, as F",
      "pel_ppm": "0.4",
      "pel_mgm3": "0.33",
      "stel_ppm": "1",
      "stel_mgm3": "0.83",
      "id": "hydrogen-fluoride-as-f-2",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrogen-fluoride-as-f-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7664393 | S | Hydrogen fluoride, as F | 0.4 | 0.33 | | 1 | 0.83"
    },
    {
      "substance": "Hydrogen peroxide",
      "cas_number": "7722-84-1",
      "pel_ppm": "1",
      "pel_mgm3": "1.4",
      "id": "hydrogen-peroxide",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrogen-peroxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Hydrogen peroxide | 7722-84-1 | 1 | 1.4 | - |"
    },
    {
      "substance": "Hydrogen peroxide, as H $2 O $2",
      "pel_ppm": "1",
      "pel_mgm3": "1.4",
      "id": "hydrogen-peroxide-as-h-2-o-2",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrogen-peroxide-as-h-2-o-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7722841 | | Hydrogen peroxide, as H $2 O $2 | 1 | 1.4"
    },
    {
      "substance": "Hydrogen selenide (as Se)",
      "cas_number": "7783-07-5",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.2",
      "id": "hydrogen-selenide-as-se",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrogen-selenide-as-se/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Hydrogen selenide (as Se) | 7783-07-5 | 0.05 | 0.2 | - |"
    },
    {
      "substance": "Hydrogen selenide, as Se",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.2",
      "id": "hydrogen-selenide-as-se-2",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrogen-selenide-as-se-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7783075 | | Hydrogen selenide, as Se | 0.05 | 0.2"
    },
    {
      "substance": "Hydrogen sulfide",
      "cas_number": "7783-06-4",
      "id": "hydrogen-sulfide",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrogen-sulfide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Hydrogen sulfide | 7783-06-4 | - | ( 2 ) | - |",
      "disagreements": []
    },
    {
      "substance": "Hydrogenated terphenyls",
      "pel_ppm": "0.5",
      "pel_mgm3": "5",
      "id": "hydrogenated-terphenyls",
      "url": "https://referencesource.org/workplace-exposure-limits/hydrogenated-terphenyls/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "61788327 | | Hydrogenated terphenyls | 0.5 | 5"
    },
    {
      "substance": "Hydroquinone",
      "cas_number": "123-31-9",
      "pel_mgm3": "2",
      "id": "hydroquinone",
      "url": "https://referencesource.org/workplace-exposure-limits/hydroquinone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Hydroquinone | 123-31-9 | - | 2 | - |"
    },
    {
      "substance": "Hydroquinone; 1,4-benezendiol",
      "pel_mgm3": "2",
      "id": "hydroquinone-1-4-benezendiol",
      "url": "https://referencesource.org/workplace-exposure-limits/hydroquinone-1-4-benezendiol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "123319 | | Hydroquinone; 1,4-benezendiol | -- | 2"
    },
    {
      "substance": "Indene",
      "pel_ppm": "10",
      "pel_mgm3": "48",
      "id": "indene",
      "url": "https://referencesource.org/workplace-exposure-limits/indene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "95136 | | Indene | 10 | 48"
    },
    {
      "substance": "Indium",
      "pel_mgm3": "0.1",
      "id": "indium",
      "url": "https://referencesource.org/workplace-exposure-limits/indium/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440746 | | Indium | -- | 0.1"
    },
    {
      "substance": "Iodine",
      "cas_number": "7553-56-2",
      "pel_ppm": "(C)0.1",
      "pel_mgm3": "(C)1",
      "id": "iodine",
      "url": "https://referencesource.org/workplace-exposure-limits/iodine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Iodine | 7553-56-2 | (C)0.1 | (C)1 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "(C)0.1",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Iodine | 7553-56-2 | (C)0.1 | (C)1 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7553562 | | Iodine | 0.1 | 1 | C",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "(C)1",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Iodine | 7553-56-2 | (C)0.1 | (C)1 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7553562 | | Iodine | 0.1 | 1 | C",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Iodoform",
      "pel_ppm": "0.6",
      "pel_mgm3": "10",
      "id": "iodoform",
      "url": "https://referencesource.org/workplace-exposure-limits/iodoform/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75478 | | Iodoform | 0.6 | 10"
    },
    {
      "substance": "IPDI; see Isophorone diisocyanate",
      "id": "ipdi-see-isophorone-diisocyanate",
      "url": "https://referencesource.org/workplace-exposure-limits/ipdi-see-isophorone-diisocyanate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "4098719 | | IPDI; see Isophorone diisocyanate"
    },
    {
      "substance": "Iron oxide fume",
      "cas_number": "1309-37-1",
      "pel_mgm3": "10",
      "id": "iron-oxide-fume",
      "url": "https://referencesource.org/workplace-exposure-limits/iron-oxide-fume/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Iron oxide fume | 1309-37-1 | - | 10 | - |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "10",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Iron oxide fume | 1309-37-1 | - | 10 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "1309371 | | Iron oxide fume | -- | 5",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Iron pentacarbonyl, as Fe",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.8",
      "stel_ppm": "0.2",
      "stel_mgm3": "1.6",
      "id": "iron-pentacarbonyl-as-fe",
      "url": "https://referencesource.org/workplace-exposure-limits/iron-pentacarbonyl-as-fe/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "13463406 | | Iron pentacarbonyl, as Fe | 0.1 | 0.8 | | 0.2 | 1.6"
    },
    {
      "substance": "Isoamyl acetate",
      "cas_number": "123-92-2",
      "pel_ppm": "100",
      "pel_mgm3": "525",
      "id": "isoamyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/isoamyl-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Isoamyl acetate | 123-92-2 | 100 | 525 | - |"
    },
    {
      "substance": "Isoamyl acetate; 3-methylbutyl acetate; see Pentyl acetate",
      "id": "isoamyl-acetate-3-methylbutyl-acetate-see-pentyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/isoamyl-acetate-3-methylbutyl-acetate-see-pentyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "123922 | | Isoamyl acetate; 3-methylbutyl acetate; see Pentyl acetate"
    },
    {
      "substance": "Isoamyl alcohol; 3-methylbutanol",
      "pel_ppm": "100",
      "pel_mgm3": "360",
      "stel_ppm": "125",
      "stel_mgm3": "450",
      "id": "isoamyl-alcohol-3-methylbutanol",
      "url": "https://referencesource.org/workplace-exposure-limits/isoamyl-alcohol-3-methylbutanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "123513 | | Isoamyl alcohol; 3-methylbutanol | 100 | 360 | | 125 | 450"
    },
    {
      "substance": "Isoamyl alcohol (primary and secondary)",
      "cas_number": "123-51-3",
      "pel_ppm": "100",
      "pel_mgm3": "360",
      "id": "isoamyl-alcohol-primary-and-secondary",
      "url": "https://referencesource.org/workplace-exposure-limits/isoamyl-alcohol-primary-and-secondary/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Isoamyl alcohol (primary and secondary) | 123-51-3 | 100 | 360 | - |"
    },
    {
      "substance": "Isobutyl acetate",
      "cas_number": "110-19-0",
      "pel_ppm": "150",
      "pel_mgm3": "700",
      "id": "isobutyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/isobutyl-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Isobutyl acetate | 110-19-0 | 150 | 700 | - |"
    },
    {
      "substance": "Isobutyl acetate; 2-methylpropyl acetate",
      "pel_ppm": "150",
      "pel_mgm3": "700",
      "id": "isobutyl-acetate-2-methylpropyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/isobutyl-acetate-2-methylpropyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "110190 | | Isobutyl acetate; 2-methylpropyl acetate | 150 | 700"
    },
    {
      "substance": "Isobutyl alcohol",
      "cas_number": "78-83-1",
      "pel_ppm": "100",
      "pel_mgm3": "300",
      "id": "isobutyl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/isobutyl-alcohol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Isobutyl alcohol | 78-83-1 | 100 | 300 | - |"
    },
    {
      "substance": "Isobutyl alcohol; 2-methylpropanol",
      "pel_ppm": "50",
      "pel_mgm3": "150",
      "id": "isobutyl-alcohol-2-methylpropanol",
      "url": "https://referencesource.org/workplace-exposure-limits/isobutyl-alcohol-2-methylpropanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78831 | | Isobutyl alcohol; 2-methylpropanol | 50 | 150"
    },
    {
      "substance": "Isoflurane",
      "pel_ppm": "2",
      "pel_mgm3": "15",
      "id": "isoflurane",
      "url": "https://referencesource.org/workplace-exposure-limits/isoflurane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "26675467 | | Isoflurane | 2 | 15"
    },
    {
      "substance": "Isooctyl alcohol",
      "pel_ppm": "50",
      "pel_mgm3": "270",
      "id": "isooctyl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/isooctyl-alcohol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "26952216 | S | Isooctyl alcohol | 50 | 270"
    },
    {
      "substance": "Isophorone",
      "cas_number": "78-59-1",
      "pel_ppm": "25",
      "pel_mgm3": "140",
      "id": "isophorone",
      "url": "https://referencesource.org/workplace-exposure-limits/isophorone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Isophorone | 78-59-1 | 25 | 140 | - |"
    },
    {
      "substance": "Isophorone; 3,5,5-trimethyl-2-cyclohexene-1-one",
      "pel_ppm": "4",
      "pel_mgm3": "23",
      "id": "isophorone-3-5-5-trimethyl-2-cyclohexene-1-one",
      "url": "https://referencesource.org/workplace-exposure-limits/isophorone-3-5-5-trimethyl-2-cyclohexene-1-one/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78591 | | Isophorone; 3,5,5-trimethyl-2-cyclohexene-1-one | 4 | 23"
    },
    {
      "substance": "Isophorone diisocyanate; IPDI",
      "pel_ppm": "0.005",
      "pel_mgm3": "0.045",
      "stel_ppm": "0.02",
      "id": "isophorone-diisocyanate-ipdi",
      "url": "https://referencesource.org/workplace-exposure-limits/isophorone-diisocyanate-ipdi/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "4098719 | S | Isophorone diisocyanate; IPDI | 0.005 | 0.045 | | 0.02 | --"
    },
    {
      "substance": "Isopropoxyethanol",
      "pel_ppm": "25",
      "pel_mgm3": "105",
      "id": "isopropoxyethanol",
      "url": "https://referencesource.org/workplace-exposure-limits/isopropoxyethanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "109591 | | Isopropoxyethanol | 25 | 105"
    },
    {
      "substance": "Isopropyl acetate",
      "cas_number": "108-21-4",
      "pel_ppm": "250",
      "pel_mgm3": "950",
      "id": "isopropyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/isopropyl-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Isopropyl acetate | 108-21-4 | 250 | 950 | - |",
      "disagreements": []
    },
    {
      "substance": "Isopropyl alcohol",
      "cas_number": "67-63-0",
      "pel_ppm": "400",
      "pel_mgm3": "980",
      "id": "isopropyl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/isopropyl-alcohol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Isopropyl alcohol | 67-63-0 | 400 | 980 | - |",
      "disagreements": []
    },
    {
      "substance": "Isopropyl ether",
      "cas_number": "108-20-3",
      "pel_ppm": "500",
      "pel_mgm3": "2100",
      "id": "isopropyl-ether",
      "url": "https://referencesource.org/workplace-exposure-limits/isopropyl-ether/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Isopropyl ether | 108-20-3 | 500 | 2100 | - |"
    },
    {
      "substance": "Isopropyl ether; diisopropyl ether",
      "pel_ppm": "250",
      "pel_mgm3": "1,050",
      "id": "isopropyl-ether-diisopropyl-ether",
      "url": "https://referencesource.org/workplace-exposure-limits/isopropyl-ether-diisopropyl-ether/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108203 | | Isopropyl ether; diisopropyl ether | 250 | 1,050"
    },
    {
      "substance": "Isopropyl glycidyl ether (IGE)",
      "cas_number": "4016-14-2",
      "pel_ppm": "50",
      "pel_mgm3": "240",
      "id": "isopropyl-glycidyl-ether-ige",
      "url": "https://referencesource.org/workplace-exposure-limits/isopropyl-glycidyl-ether-ige/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Isopropyl glycidyl ether (IGE) | 4016-14-2 | 50 | 240 | - |"
    },
    {
      "substance": "Isopropyl glycidyl ether; IGE; 1,2-epoxy-3-isopropoxypropane",
      "pel_ppm": "50",
      "pel_mgm3": "240",
      "stel_ppm": "75",
      "stel_mgm3": "360",
      "id": "isopropyl-glycidyl-ether-ige-1-2-epoxy-3-isopropoxypropane",
      "url": "https://referencesource.org/workplace-exposure-limits/isopropyl-glycidyl-ether-ige-1-2-epoxy-3-isopropoxypropane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "4016142 | | Isopropyl glycidyl ether; IGE; 1,2-epoxy-3-isopropoxypropane | 50 | 240 | | 75 | 360"
    },
    {
      "substance": "Isopropylamine",
      "cas_number": "75-31-0",
      "pel_ppm": "5",
      "pel_mgm3": "12",
      "id": "isopropylamine",
      "url": "https://referencesource.org/workplace-exposure-limits/isopropylamine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Isopropylamine | 75-31-0 | 5 | 12 | - |",
      "disagreements": []
    },
    {
      "substance": "Kaolin",
      "cas_number": "1332-58-7",
      "id": "kaolin",
      "url": "https://referencesource.org/workplace-exposure-limits/kaolin/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Kaolin | 1332-58-7 | - | - | - |"
    },
    {
      "substance": "Kaolin; (respirable dust containing no asbestos and <1% crystaline silica)",
      "pel_mgm3": "2",
      "id": "kaolin-respirable-dust-containing-no-asbestos-and-1-crystaline-silica",
      "url": "https://referencesource.org/workplace-exposure-limits/kaolin-respirable-dust-containing-no-asbestos-and-1-crystaline-silica/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1332587 | | Kaolin; (respirable dust containing no asbestos and <1% crystaline silica) | -- | 2"
    },
    {
      "substance": "Ketene",
      "cas_number": "463-51-4",
      "pel_ppm": "0.5",
      "pel_mgm3": "0.9",
      "id": "ketene",
      "url": "https://referencesource.org/workplace-exposure-limits/ketene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ketene | 463-51-4 | 0.5 | 0.9 | - |"
    },
    {
      "substance": "Ketene; ethenone",
      "pel_ppm": "0.5",
      "pel_mgm3": "0.9",
      "stel_ppm": "1.5",
      "stel_mgm3": "3",
      "id": "ketene-ethenone",
      "url": "https://referencesource.org/workplace-exposure-limits/ketene-ethenone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "463514 | | Ketene; ethenone | 0.5 | 0.9 | | 1.5 | 3"
    },
    {
      "substance": "L.P.G. (Liquefied petroleum gas)",
      "cas_number": "68476-85-7",
      "pel_ppm": "1000",
      "pel_mgm3": "1800",
      "id": "l-p-g-liquefied-petroleum-gas",
      "url": "https://referencesource.org/workplace-exposure-limits/l-p-g-liquefied-petroleum-gas/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "L.P.G. (Liquefied petroleum gas) | 68476-85-7 | 1000 | 1800 | - |"
    },
    {
      "substance": "Lead chromate, as Pb",
      "pel_mgm3": "0.01",
      "id": "lead-chromate-as-pb",
      "url": "https://referencesource.org/workplace-exposure-limits/lead-chromate-as-pb/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7758976 | | Lead chromate, as Pb | -- | 0.01"
    },
    {
      "substance": "Lead, inorganic (as Pb); see 1910.1025",
      "cas_number": "7439-92-1",
      "id": "lead-inorganic-as-pb-see-1910-1025",
      "url": "https://referencesource.org/workplace-exposure-limits/lead-inorganic-as-pb-see-1910-1025/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Lead, inorganic (as Pb); see 1910.1025 | 7439-92-1 | - | - | - |"
    },
    {
      "substance": "Lead (metallic) and inorganic compounds, dust and fume, as Pb",
      "pel_mgm3": "0.01",
      "id": "lead-metallic-and-inorganic-compounds-dust-and-fume-as-pb",
      "url": "https://referencesource.org/workplace-exposure-limits/lead-metallic-and-inorganic-compounds-dust-and-fume-as-pb/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7439921 | | Lead (metallic) and inorganic compounds, dust and fume, as Pb | -- | 0.01"
    },
    {
      "substance": "Lead tetraethyl, see Tetraethyl lead",
      "id": "lead-tetraethyl-see-tetraethyl-lead",
      "url": "https://referencesource.org/workplace-exposure-limits/lead-tetraethyl-see-tetraethyl-lead/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78002 | | Lead tetraethyl, see Tetraethyl lead"
    },
    {
      "substance": "Lead tetramethyl, see Tetramethyl lead",
      "id": "lead-tetramethyl-see-tetramethyl-lead",
      "url": "https://referencesource.org/workplace-exposure-limits/lead-tetramethyl-see-tetramethyl-lead/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75741 | | Lead tetramethyl, see Tetramethyl lead"
    },
    {
      "substance": "Limestone",
      "cas_number": "1317-65-3",
      "id": "limestone",
      "url": "https://referencesource.org/workplace-exposure-limits/limestone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Limestone | 1317-65-3 | - | - | - |"
    },
    {
      "substance": "Limestone; calcium carbonate; see Particulates not otherwise regulated",
      "id": "limestone-calcium-carbonate-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/limestone-calcium-carbonate-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1317653 | | Limestone; calcium carbonate; see Particulates not otherwise regulated"
    },
    {
      "substance": "Lindane",
      "cas_number": "58-89-9",
      "pel_mgm3": "0.5",
      "id": "lindane",
      "url": "https://referencesource.org/workplace-exposure-limits/lindane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Lindane | 58-89-9 | - | 0.5 | X |"
    },
    {
      "substance": "Lindane; 1,2,3,4,5,6-hexachlorocyclohexane, gamma isomer",
      "pel_mgm3": "0.5",
      "id": "lindane-1-2-3-4-5-6-hexachlorocyclohexane-gamma-isomer",
      "url": "https://referencesource.org/workplace-exposure-limits/lindane-1-2-3-4-5-6-hexachlorocyclohexane-gamma-isomer/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "58899 | S | Lindane; 1,2,3,4,5,6-hexachlorocyclohexane, gamma isomer | -- | 0.5"
    },
    {
      "substance": "Lithium hydride",
      "cas_number": "7580-67-8",
      "pel_mgm3": "0.025",
      "id": "lithium-hydride",
      "url": "https://referencesource.org/workplace-exposure-limits/lithium-hydride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Lithium hydride | 7580-67-8 | - | 0.025 | - |",
      "disagreements": []
    },
    {
      "substance": "Lithium stearate",
      "pel_mgm3": "10",
      "id": "lithium-stearate",
      "url": "https://referencesource.org/workplace-exposure-limits/lithium-stearate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "4485125 | | Lithium stearate | -- | 10"
    },
    {
      "substance": "m-isomer",
      "cas_number": "99-08-1",
      "id": "m-isomer",
      "url": "https://referencesource.org/workplace-exposure-limits/m-isomer/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "m-isomer | 99-08-1 | - | - | - |"
    },
    {
      "substance": "m-Phthalodinitrile",
      "pel_mgm3": "5",
      "id": "m-phthalodinitrile",
      "url": "https://referencesource.org/workplace-exposure-limits/m-phthalodinitrile/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "626175 | | m-Phthalodinitrile | -- | 5"
    },
    {
      "substance": "m-Toluidine",
      "pel_ppm": "2",
      "pel_mgm3": "9",
      "id": "m-toluidine",
      "url": "https://referencesource.org/workplace-exposure-limits/m-toluidine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108441 | S | m-Toluidine | 2 | 9"
    },
    {
      "substance": "m-Xylene-a,a\u2032-diamine",
      "pel_mgm3": "0.1",
      "ceiling": "C",
      "id": "m-xylene-a-a-diamine",
      "url": "https://referencesource.org/workplace-exposure-limits/m-xylene-a-a-diamine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1477550 | S | m-Xylene-a,a\u2032-diamine | -- | 0.1 | C"
    },
    {
      "substance": "Magnesite",
      "cas_number": "546-93-0",
      "id": "magnesite",
      "url": "https://referencesource.org/workplace-exposure-limits/magnesite/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Magnesite | 546-93-0 | - | - | - |"
    },
    {
      "substance": "Magnesite; magnesium carbonate; see Particulates not otherwise regulated",
      "id": "magnesite-magnesium-carbonate-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/magnesite-magnesium-carbonate-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "13717005 | | Magnesite; magnesium carbonate; see Particulates not otherwise regulated"
    },
    {
      "substance": "Magnesium oxide fume",
      "cas_number": "1309-48-4",
      "id": "magnesium-oxide-fume",
      "url": "https://referencesource.org/workplace-exposure-limits/magnesium-oxide-fume/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Magnesium oxide fume | 1309-48-4 | - | - | - |"
    },
    {
      "substance": "Magnesium oxide fume, as Mg",
      "pel_mgm3": "10",
      "id": "magnesium-oxide-fume-as-mg",
      "url": "https://referencesource.org/workplace-exposure-limits/magnesium-oxide-fume-as-mg/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1309484 | | Magnesium oxide fume, as Mg | -- | 10"
    },
    {
      "substance": "Magnesium stearate",
      "pel_mgm3": "10",
      "id": "magnesium-stearate",
      "url": "https://referencesource.org/workplace-exposure-limits/magnesium-stearate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "557040 | | Magnesium stearate | -- | 10"
    },
    {
      "substance": "Malathion",
      "cas_number": "121-75-5",
      "id": "malathion",
      "url": "https://referencesource.org/workplace-exposure-limits/malathion/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Malathion | 121-75-5 | - | - | - |"
    },
    {
      "substance": "Malathion; o,o-dimethyl S-1(1,2-dicarboethyoxyethyl) phosphorodithioate",
      "pel_mgm3": "10",
      "id": "malathion-o-o-dimethyl-s-1-1-2-dicarboethyoxyethyl-phosphorodithioate",
      "url": "https://referencesource.org/workplace-exposure-limits/malathion-o-o-dimethyl-s-1-1-2-dicarboethyoxyethyl-phosphorodithioate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "121755 | S | Malathion; o,o-dimethyl S-1(1,2-dicarboethyoxyethyl) phosphorodithioate | -- | 10"
    },
    {
      "substance": "Maleic anhydride",
      "cas_number": "108-31-6",
      "pel_ppm": "0.25",
      "pel_mgm3": "1",
      "id": "maleic-anhydride",
      "url": "https://referencesource.org/workplace-exposure-limits/maleic-anhydride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Maleic anhydride | 108-31-6 | 0.25 | 1 | - |"
    },
    {
      "substance": "Maleic anhydride; cis-butenedioic anhydride",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.4",
      "id": "maleic-anhydride-cis-butenedioic-anhydride",
      "url": "https://referencesource.org/workplace-exposure-limits/maleic-anhydride-cis-butenedioic-anhydride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108316 | | Maleic anhydride; cis-butenedioic anhydride | 0.1 | 0.4"
    },
    {
      "substance": "Manganese compounds (as Mn)",
      "cas_number": "7439-96-5",
      "pel_mgm3": "(C)5",
      "id": "manganese-compounds-as-mn",
      "url": "https://referencesource.org/workplace-exposure-limits/manganese-compounds-as-mn/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Manganese compounds (as Mn) | 7439-96-5 | - | (C)5 | - |"
    },
    {
      "substance": "Manganese, cyclopentadienyl-tricarbonyl, as Mn",
      "pel_mgm3": "0.1",
      "id": "manganese-cyclopentadienyl-tricarbonyl-as-mn",
      "url": "https://referencesource.org/workplace-exposure-limits/manganese-cyclopentadienyl-tricarbonyl-as-mn/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "12079651 | S | Manganese, cyclopentadienyl-tricarbonyl, as Mn | -- | 0.1"
    },
    {
      "substance": "Manganese fume (as Mn)",
      "cas_number": "7439-96-5",
      "pel_mgm3": "(C)5",
      "id": "manganese-fume-as-mn",
      "url": "https://referencesource.org/workplace-exposure-limits/manganese-fume-as-mn/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Manganese fume (as Mn) | 7439-96-5 | - | (C)5 | - |"
    },
    {
      "substance": "Manganese fume, as Mn",
      "pel_mgm3": "0.2",
      "stel_mgm3": "3",
      "id": "manganese-fume-as-mn-2",
      "url": "https://referencesource.org/workplace-exposure-limits/manganese-fume-as-mn-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7439965 | | Manganese fume, as Mn | -- | 0.2 | | -- | 3"
    },
    {
      "substance": "Marble",
      "cas_number": "1317-65-3",
      "id": "marble",
      "url": "https://referencesource.org/workplace-exposure-limits/marble/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Marble | 1317-65-3 | - | - | - |"
    },
    {
      "substance": "MDA; see 4,4\u2032-Methylene dianiline",
      "id": "mda-see-4-4-methylene-dianiline",
      "url": "https://referencesource.org/workplace-exposure-limits/mda-see-4-4-methylene-dianiline/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "101779 | S | MDA; see 4,4\u2032-Methylene dianiline"
    },
    {
      "substance": "MDI; see Methylene bis(phenylisocyanate)",
      "id": "mdi-see-methylene-bis-phenylisocyanate",
      "url": "https://referencesource.org/workplace-exposure-limits/mdi-see-methylene-bis-phenylisocyanate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "101688 | | MDI; see Methylene bis(phenylisocyanate)"
    },
    {
      "substance": "Mercury alkyls, as Hg",
      "pel_mgm3": "0.01",
      "ceiling": "0.04 mg/M 3",
      "stel_mgm3": "0.03",
      "id": "mercury-alkyls-as-hg",
      "url": "https://referencesource.org/workplace-exposure-limits/mercury-alkyls-as-hg/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7439976 | S | Mercury alkyls, as Hg | -- | 0.01 | 0.04 mg/M 3 | -- | 0.03"
    },
    {
      "substance": "Mercury (aryl and inorganic) (as Hg)",
      "cas_number": "7439-97-6",
      "id": "mercury-aryl-and-inorganic-as-hg",
      "url": "https://referencesource.org/workplace-exposure-limits/mercury-aryl-and-inorganic-as-hg/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Mercury (aryl and inorganic) (as Hg) | 7439-97-6 | - | ( 2 ) | - |"
    },
    {
      "substance": "Mercury aryl compounds as Hg",
      "pel_mgm3": "0.1",
      "ceiling": "C",
      "id": "mercury-aryl-compounds-as-hg",
      "url": "https://referencesource.org/workplace-exposure-limits/mercury-aryl-compounds-as-hg/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7439976 | S | Mercury aryl compounds as Hg | | 0.1 | C"
    },
    {
      "substance": "Mercury, metallic and inorganic compounds as Hg",
      "pel_mgm3": "0.025",
      "ceiling": "0.1 mg/M 3",
      "id": "mercury-metallic-and-inorganic-compounds-as-hg",
      "url": "https://referencesource.org/workplace-exposure-limits/mercury-metallic-and-inorganic-compounds-as-hg/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7439976 | S | Mercury, metallic and inorganic compounds as Hg | -- | 0.025 | 0.1 mg/M 3"
    },
    {
      "substance": "Mercury (organo) alkyl compounds (as Hg)",
      "cas_number": "7439-97-6",
      "id": "mercury-organo-alkyl-compounds-as-hg",
      "url": "https://referencesource.org/workplace-exposure-limits/mercury-organo-alkyl-compounds-as-hg/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Mercury (organo) alkyl compounds (as Hg) | 7439-97-6 | - | ( 2 ) | - |"
    },
    {
      "substance": "Mercury (vapor) (as Hg)",
      "cas_number": "7439-97-6",
      "id": "mercury-vapor-as-hg",
      "url": "https://referencesource.org/workplace-exposure-limits/mercury-vapor-as-hg/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Mercury (vapor) (as Hg) | 7439-97-6 | - | ( 2 ) | - |"
    },
    {
      "substance": "Mesityl oxide",
      "cas_number": "141-79-7",
      "pel_ppm": "25",
      "pel_mgm3": "100",
      "id": "mesityl-oxide",
      "url": "https://referencesource.org/workplace-exposure-limits/mesityl-oxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Mesityl oxide | 141-79-7 | 25 | 100 | - |"
    },
    {
      "substance": "Mesityl oxide; 4-methyl-3-pentene-2-one",
      "pel_ppm": "15",
      "pel_mgm3": "60",
      "stel_ppm": "25",
      "stel_mgm3": "100",
      "id": "mesityl-oxide-4-methyl-3-pentene-2-one",
      "url": "https://referencesource.org/workplace-exposure-limits/mesityl-oxide-4-methyl-3-pentene-2-one/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "141797 | | Mesityl oxide; 4-methyl-3-pentene-2-one | 15 | 60 | | 25 | 100"
    },
    {
      "substance": "Mesitylene; see 1,3,5-Trimethylbenzene",
      "id": "mesitylene-see-1-3-5-trimethylbenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/mesitylene-see-1-3-5-trimethylbenzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108678 | | Mesitylene; see 1,3,5-Trimethylbenzene"
    },
    {
      "substance": "(meta)",
      "cas_number": "99-65-0",
      "id": "meta",
      "url": "https://referencesource.org/workplace-exposure-limits/meta/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "(meta) | 99-65-0 | - | - | - |"
    },
    {
      "substance": "Methacrylic acid",
      "pel_ppm": "20",
      "pel_mgm3": "70",
      "id": "methacrylic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/methacrylic-acid/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "79414 | S | Methacrylic acid | 20 | 70"
    },
    {
      "substance": "Methane",
      "id": "methane",
      "url": "https://referencesource.org/workplace-exposure-limits/methane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74828 | | Methane | (h) | --"
    },
    {
      "substance": "Methanethiol; see Methyl mercaptan",
      "id": "methanethiol-see-methyl-mercaptan",
      "url": "https://referencesource.org/workplace-exposure-limits/methanethiol-see-methyl-mercaptan/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74931 | | Methanethiol; see Methyl mercaptan"
    },
    {
      "substance": "Methanol; see Methyl alcohol",
      "id": "methanol-see-methyl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/methanol-see-methyl-alcohol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "67561 | | Methanol; see Methyl alcohol"
    },
    {
      "substance": "Methomyl",
      "pel_mgm3": "2.5",
      "id": "methomyl",
      "url": "https://referencesource.org/workplace-exposure-limits/methomyl/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "16752775 | S | Methomyl | -- | 2.5"
    },
    {
      "substance": "Methoxychlor",
      "cas_number": "72-43-5",
      "id": "methoxychlor",
      "url": "https://referencesource.org/workplace-exposure-limits/methoxychlor/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methoxychlor | 72-43-5 | - | - | - |"
    },
    {
      "substance": "Methoxychlor; 1,1,1-trichloro-2, 2-bis(p-methoxyphenyl)ethane",
      "pel_mgm3": "10",
      "id": "methoxychlor-1-1-1-trichloro-2-2-bis-p-methoxyphenyl-ethane",
      "url": "https://referencesource.org/workplace-exposure-limits/methoxychlor-1-1-1-trichloro-2-2-bis-p-methoxyphenyl-ethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "72435 | | Methoxychlor; 1,1,1-trichloro-2, 2-bis(p-methoxyphenyl)ethane | -- | 10"
    },
    {
      "substance": "Methoxyflurane",
      "pel_ppm": "2",
      "pel_mgm3": "13",
      "id": "methoxyflurane",
      "url": "https://referencesource.org/workplace-exposure-limits/methoxyflurane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "76380 | | Methoxyflurane | 2 | 13"
    },
    {
      "substance": "Methyl 2-cyanoacrylate",
      "pel_ppm": "0.2",
      "pel_mgm3": "0.908",
      "id": "methyl-2-cyanoacrylate",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-2-cyanoacrylate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "137053 | | Methyl 2-cyanoacrylate | 0.2 | 0.908"
    },
    {
      "substance": "Methyl acetate",
      "cas_number": "79-20-9",
      "pel_ppm": "200",
      "pel_mgm3": "610",
      "id": "methyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl acetate | 79-20-9 | 200 | 610 | - |",
      "disagreements": []
    },
    {
      "substance": "Methyl acetylene (Propyne)",
      "cas_number": "74-99-7",
      "pel_ppm": "1000",
      "pel_mgm3": "1650",
      "id": "methyl-acetylene-propyne",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-acetylene-propyne/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl acetylene (Propyne) | 74-99-7 | 1000 | 1650 | - |"
    },
    {
      "substance": "Methyl acetylene; propyne",
      "pel_ppm": "1,000",
      "pel_mgm3": "1,650",
      "id": "methyl-acetylene-propyne-2",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-acetylene-propyne-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74997 | | Methyl acetylene; propyne | 1,000 | 1,650"
    },
    {
      "substance": "Methyl acrylate",
      "cas_number": "96-33-3",
      "pel_ppm": "10",
      "pel_mgm3": "35",
      "id": "methyl-acrylate",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-acrylate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl acrylate | 96-33-3 | 10 | 35 | X |",
      "disagreements": []
    },
    {
      "substance": "Methyl alcohol",
      "cas_number": "67-56-1",
      "pel_ppm": "200",
      "pel_mgm3": "260",
      "id": "methyl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-alcohol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl alcohol | 67-56-1 | 200 | 260 | - |"
    },
    {
      "substance": "Methyl alcohol; methanol",
      "pel_ppm": "200",
      "pel_mgm3": "260",
      "ceiling": "1000 ppm",
      "stel_ppm": "250",
      "stel_mgm3": "325",
      "id": "methyl-alcohol-methanol",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-alcohol-methanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "67561 | S | Methyl alcohol; methanol | 200 | 260 | 1000 ppm | 250 | 325"
    },
    {
      "substance": "Methyl amyl alcohol; see Methyl isobutyl carbinol",
      "id": "methyl-amyl-alcohol-see-methyl-isobutyl-carbinol",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-amyl-alcohol-see-methyl-isobutyl-carbinol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108112 | | Methyl amyl alcohol; see Methyl isobutyl carbinol"
    },
    {
      "substance": "Methyl bromide",
      "cas_number": "74-83-9",
      "pel_ppm": "(C)20",
      "pel_mgm3": "(C)80",
      "id": "methyl-bromide",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-bromide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl bromide | 74-83-9 | (C)20 | (C)80 | X |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "(C)20",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Methyl bromide | 74-83-9 | (C)20 | (C)80 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "74839 | S | Methyl bromide | 1 | 3.88 | 20 ppm",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "(C)80",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Methyl bromide | 74-83-9 | (C)20 | (C)80 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "3.88",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "74839 | S | Methyl bromide | 1 | 3.88 | 20 ppm",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Methyl chloride",
      "cas_number": "74-87-3",
      "id": "methyl-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-chloride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl chloride | 74-87-3 | - | ( 2 ) | - |",
      "disagreements": []
    },
    {
      "substance": "Methyl chloroform (1,1,1-Trichloroethane)",
      "cas_number": "71-55-6",
      "pel_ppm": "350",
      "pel_mgm3": "1900",
      "id": "methyl-chloroform-1-1-1-trichloroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-chloroform-1-1-1-trichloroethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl chloroform (1,1,1-Trichloroethane) | 71-55-6 | 350 | 1900 | - |"
    },
    {
      "substance": "Methyl chloroform; 1,1,1-trichloroethane",
      "pel_ppm": "350",
      "pel_mgm3": "1900",
      "ceiling": "800 ppm",
      "stel_ppm": "450",
      "stel_mgm3": "2450",
      "id": "methyl-chloroform-1-1-1-trichloroethane-2",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-chloroform-1-1-1-trichloroethane-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "71556 | | Methyl chloroform; 1,1,1-trichloroethane | 350 | 1900 | 800 ppm | 450 | 2450"
    },
    {
      "substance": "Methyl chloromethyl ether; see Section 5209",
      "id": "methyl-chloromethyl-ether-see-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-chloromethyl-ether-see-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107302 | | Methyl chloromethyl ether; see Section 5209"
    },
    {
      "substance": "Methyl cyanide; see Acetonitrile",
      "id": "methyl-cyanide-see-acetonitrile",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-cyanide-see-acetonitrile/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75058 | | Methyl cyanide; see Acetonitrile"
    },
    {
      "substance": "Methyl demeton; a mixture of o,o-dimethyl o-(2-(ethylthio)ethyl) phosphorothioate and o,o-dimethyl S-(2-(ethylthio)-ethyl) phosphorothioate",
      "pel_mgm3": "0.5",
      "id": "methyl-demeton-a-mixture-of-o-o-dimethyl-o-2-ethylthio-ethyl-phosphorothioate-an",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-demeton-a-mixture-of-o-o-dimethyl-o-2-ethylthio-ethyl-phosphorothioate-an/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "8022002 | S | Methyl demeton; a mixture of o,o-dimethyl o-(2-(ethylthio)ethyl) phosphorothioate and o,o-dimethyl S-(2-(ethylthio)-ethyl) phosphorothioate | -- | 0.5"
    },
    {
      "substance": "Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone",
      "pel_ppm": "200",
      "pel_mgm3": "590",
      "stel_ppm": "300",
      "stel_mgm3": "885",
      "id": "methyl-ethyl-ketone-mek-2-butanone-ethyl-methyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-ethyl-ketone-mek-2-butanone-ethyl-methyl-ketone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78933 | | Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone | 200 | 590 | | 300 | 885"
    },
    {
      "substance": "Methyl ethyl ketone peroxide",
      "pel_ppm": "0.2",
      "pel_mgm3": "1.5",
      "ceiling": "C",
      "id": "methyl-ethyl-ketone-peroxide",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-ethyl-ketone-peroxide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1338234 | | Methyl ethyl ketone peroxide | 0.2 | 1.5 | C"
    },
    {
      "substance": "Methyl formate",
      "cas_number": "107-31-3",
      "pel_ppm": "100",
      "pel_mgm3": "250",
      "id": "methyl-formate",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-formate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl formate | 107-31-3 | 100 | 250 | - |",
      "disagreements": []
    },
    {
      "substance": "Methyl hydrazine (Monomethyl hydrazine)",
      "cas_number": "60-34-4",
      "pel_ppm": "(C)0.2",
      "pel_mgm3": "(C)0.35",
      "id": "methyl-hydrazine-monomethyl-hydrazine",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-hydrazine-monomethyl-hydrazine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl hydrazine (Monomethyl hydrazine) | 60-34-4 | (C)0.2 | (C)0.35 | X |"
    },
    {
      "substance": "Methyl hydrazine; monomethyl hydrazine",
      "pel_ppm": "0.01",
      "pel_mgm3": "0.019",
      "id": "methyl-hydrazine-monomethyl-hydrazine-2",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-hydrazine-monomethyl-hydrazine-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "60344 | S | Methyl hydrazine; monomethyl hydrazine | 0.01 | 0.019"
    },
    {
      "substance": "Methyl iodide",
      "cas_number": "74-88-4",
      "pel_ppm": "5",
      "pel_mgm3": "28",
      "id": "methyl-iodide",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-iodide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl iodide | 74-88-4 | 5 | 28 | X |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "5",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Methyl iodide | 74-88-4 | 5 | 28 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "2",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "74884 | S | Methyl iodide | 2 | 10",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "28",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Methyl iodide | 74-88-4 | 5 | 28 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "10",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "74884 | S | Methyl iodide | 2 | 10",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Methyl isoamyl ketone",
      "cas_number": "110-12-3",
      "pel_ppm": "100",
      "pel_mgm3": "475",
      "id": "methyl-isoamyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-isoamyl-ketone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl isoamyl ketone | 110-12-3 | 100 | 475 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "100",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Methyl isoamyl ketone | 110-12-3 | 100 | 475 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "50",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "110123 | | Methyl isoamyl ketone | 50 | 234",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "475",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Methyl isoamyl ketone | 110-12-3 | 100 | 475 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "234",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "110123 | | Methyl isoamyl ketone | 50 | 234",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Methyl isobutyl carbinol",
      "cas_number": "108-11-2",
      "pel_ppm": "25",
      "pel_mgm3": "100",
      "id": "methyl-isobutyl-carbinol",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-isobutyl-carbinol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl isobutyl carbinol | 108-11-2 | 25 | 100 | X |"
    },
    {
      "substance": "Methyl isobutyl carbinol; 4-methyl-2-pentanol; methyl amyl alcohol",
      "pel_ppm": "25",
      "pel_mgm3": "100",
      "stel_ppm": "40",
      "stel_mgm3": "165",
      "id": "methyl-isobutyl-carbinol-4-methyl-2-pentanol-methyl-amyl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-isobutyl-carbinol-4-methyl-2-pentanol-methyl-amyl-alcohol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108112 | S | Methyl isobutyl carbinol; 4-methyl-2-pentanol; methyl amyl alcohol | 25 | 100 | | 40 | 165"
    },
    {
      "substance": "Methyl isobutyl ketone; Hexone",
      "pel_ppm": "50",
      "pel_mgm3": "205",
      "stel_ppm": "75",
      "stel_mgm3": "300",
      "id": "methyl-isobutyl-ketone-hexone",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-isobutyl-ketone-hexone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108101 | | Methyl isobutyl ketone; Hexone | 50 | 205 | | 75 | 300"
    },
    {
      "substance": "Methyl isocyanate",
      "cas_number": "624-83-9",
      "pel_ppm": "0.02",
      "pel_mgm3": "0.05",
      "id": "methyl-isocyanate",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-isocyanate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl isocyanate | 624-83-9 | 0.02 | 0.05 | X |",
      "disagreements": []
    },
    {
      "substance": "Methyl isopropyl ketone",
      "pel_ppm": "200",
      "pel_mgm3": "705",
      "id": "methyl-isopropyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-isopropyl-ketone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "563804 | | Methyl isopropyl ketone | 200 | 705"
    },
    {
      "substance": "Methyl mercaptan",
      "cas_number": "74-93-1",
      "pel_ppm": "(C)10",
      "pel_mgm3": "(C)20",
      "id": "methyl-mercaptan",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-mercaptan/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl mercaptan | 74-93-1 | (C)10 | (C)20 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "(C)10",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Methyl mercaptan | 74-93-1 | (C)10 | (C)20 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "74931 | | Methyl mercaptan | 0.5 | 1",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "(C)20",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Methyl mercaptan | 74-93-1 | (C)10 | (C)20 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "74931 | | Methyl mercaptan | 0.5 | 1",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Methyl methacrylate",
      "cas_number": "80-62-6",
      "pel_ppm": "100",
      "pel_mgm3": "410",
      "id": "methyl-methacrylate",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-methacrylate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl methacrylate | 80-62-6 | 100 | 410 | - |"
    },
    {
      "substance": "Methyl methacrylate; methyl 2-methyl-2-propenoate",
      "pel_ppm": "50",
      "pel_mgm3": "205",
      "stel_ppm": "100",
      "stel_mgm3": "410",
      "id": "methyl-methacrylate-methyl-2-methyl-2-propenoate",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-methacrylate-methyl-2-methyl-2-propenoate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "80626 | | Methyl methacrylate; methyl 2-methyl-2-propenoate | 50 | 205 | | 100 | 410"
    },
    {
      "substance": "Methyl n-amyl ketone",
      "cas_number": "110-43-0",
      "pel_ppm": "100",
      "pel_mgm3": "465",
      "id": "methyl-n-amyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-n-amyl-ketone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methyl n-amyl ketone | 110-43-0 | 100 | 465 | - |"
    },
    {
      "substance": "Methyl n-amyl ketone; 2-heptanone",
      "pel_ppm": "50",
      "pel_mgm3": "235",
      "id": "methyl-n-amyl-ketone-2-heptanone",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-n-amyl-ketone-2-heptanone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "110430 | | Methyl n-amyl ketone; 2-heptanone | 50 | 235"
    },
    {
      "substance": "Methyl n-butyl ketone; 2-hexanone",
      "pel_ppm": "1",
      "pel_mgm3": "4",
      "stel_ppm": "10",
      "stel_mgm3": "40",
      "id": "methyl-n-butyl-ketone-2-hexanone",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-n-butyl-ketone-2-hexanone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "591786 | S | Methyl n-butyl ketone; 2-hexanone | 1 | 4 | | 10 | 40"
    },
    {
      "substance": "Methyl parathion; o,o-dimethyl o-(p-nitrophenyl) phosphorothioate",
      "pel_mgm3": "0.2",
      "id": "methyl-parathion-o-o-dimethyl-o-p-nitrophenyl-phosphorothioate",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-parathion-o-o-dimethyl-o-p-nitrophenyl-phosphorothioate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "298000 | S | Methyl parathion; o,o-dimethyl o-(p-nitrophenyl) phosphorothioate | -- | 0.2"
    },
    {
      "substance": "Methyl propyl ketone; 2-pentanone",
      "pel_ppm": "200",
      "pel_mgm3": "700",
      "stel_ppm": "250",
      "stel_mgm3": "875",
      "id": "methyl-propyl-ketone-2-pentanone",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-propyl-ketone-2-pentanone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107879 | | Methyl propyl ketone; 2-pentanone | 200 | 700 | | 250 | 875"
    },
    {
      "substance": "Methyl silicate; tetramethyl silicate",
      "pel_ppm": "1",
      "pel_mgm3": "6",
      "id": "methyl-silicate-tetramethyl-silicate",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-silicate-tetramethyl-silicate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "681845 | | Methyl silicate; tetramethyl silicate | 1 | 6"
    },
    {
      "substance": "Methyl sulfate; see Dimethyl sulfate",
      "id": "methyl-sulfate-see-dimethyl-sulfate",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-sulfate-see-dimethyl-sulfate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "77781 | | Methyl sulfate; see Dimethyl sulfate"
    },
    {
      "substance": "Methyl tert-butyl ether; MTBE",
      "pel_ppm": "40",
      "pel_mgm3": "144",
      "id": "methyl-tert-butyl-ether-mtbe",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-tert-butyl-ether-mtbe/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1634044 | | Methyl tert-butyl ether; MTBE | 40 | 144"
    },
    {
      "substance": "Methyl vinyl ketone",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.14",
      "ceiling": "C",
      "id": "methyl-vinyl-ketone",
      "url": "https://referencesource.org/workplace-exposure-limits/methyl-vinyl-ketone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78944 | S | Methyl vinyl ketone | 0.05 | 0.14 | C"
    },
    {
      "substance": "Methylal (Dimethoxy-methane)",
      "cas_number": "109-87-5",
      "pel_ppm": "1000",
      "pel_mgm3": "3100",
      "id": "methylal-dimethoxy-methane",
      "url": "https://referencesource.org/workplace-exposure-limits/methylal-dimethoxy-methane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methylal (Dimethoxy-methane) | 109-87-5 | 1000 | 3100 | - |"
    },
    {
      "substance": "Methylal; dimethoxymethane",
      "pel_ppm": "1,000",
      "pel_mgm3": "3,100",
      "id": "methylal-dimethoxymethane",
      "url": "https://referencesource.org/workplace-exposure-limits/methylal-dimethoxymethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "109875 | | Methylal; dimethoxymethane | 1,000 | 3,100"
    },
    {
      "substance": "Methylamine",
      "cas_number": "74-89-5",
      "pel_ppm": "10",
      "pel_mgm3": "12",
      "id": "methylamine",
      "url": "https://referencesource.org/workplace-exposure-limits/methylamine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methylamine | 74-89-5 | 10 | 12 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "10",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Methylamine | 74-89-5 | 10 | 12 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "74895 | | Methylamine | 5 | 6.4 | | 15 | 19",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "12",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Methylamine | 74-89-5 | 10 | 12 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "6.4",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "74895 | | Methylamine | 5 | 6.4 | | 15 | 19",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Methylcyclohexane",
      "cas_number": "108-87-2",
      "pel_ppm": "500",
      "pel_mgm3": "2000",
      "id": "methylcyclohexane",
      "url": "https://referencesource.org/workplace-exposure-limits/methylcyclohexane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methylcyclohexane | 108-87-2 | 500 | 2000 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "500",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Methylcyclohexane | 108-87-2 | 500 | 2000 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "400",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "108872 | | Methylcyclohexane | 400 | 1,600",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "2000",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Methylcyclohexane | 108-87-2 | 500 | 2000 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1,600",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "108872 | | Methylcyclohexane | 400 | 1,600",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Methylcyclohexanol",
      "cas_number": "25639-42-3",
      "pel_ppm": "100",
      "pel_mgm3": "470",
      "id": "methylcyclohexanol",
      "url": "https://referencesource.org/workplace-exposure-limits/methylcyclohexanol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methylcyclohexanol | 25639-42-3 | 100 | 470 | - |"
    },
    {
      "substance": "Methylcyclohexanol (meta- and para-isomer mixture)",
      "pel_ppm": "50",
      "pel_mgm3": "235",
      "id": "methylcyclohexanol-meta-and-para-isomer-mixture",
      "url": "https://referencesource.org/workplace-exposure-limits/methylcyclohexanol-meta-and-para-isomer-mixture/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "25639423 | | Methylcyclohexanol (meta- and para-isomer mixture) | 50 | 235"
    },
    {
      "substance": "Methylene bis(4-cyclohexylisocyanate); hydrogenated MDI",
      "pel_ppm": "0.005",
      "pel_mgm3": "0.054",
      "id": "methylene-bis-4-cyclohexylisocyanate-hydrogenated-mdi",
      "url": "https://referencesource.org/workplace-exposure-limits/methylene-bis-4-cyclohexylisocyanate-hydrogenated-mdi/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "5124301 | | Methylene bis(4-cyclohexylisocyanate); hydrogenated MDI | 0.005 | 0.054"
    },
    {
      "substance": "Methylene bis(phenylisocyanate); MDI; diphenylmethane diisocyanate",
      "pel_ppm": "0.005",
      "pel_mgm3": "0.051",
      "id": "methylene-bis-phenylisocyanate-mdi-diphenylmethane-diisocyanate",
      "url": "https://referencesource.org/workplace-exposure-limits/methylene-bis-phenylisocyanate-mdi-diphenylmethane-diisocyanate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "101688 | | Methylene bis(phenylisocyanate); MDI; diphenylmethane diisocyanate | 0.005 | 0.051"
    },
    {
      "substance": "Methylene bisphenyl isocyanate (MDI)",
      "cas_number": "101-68-8",
      "pel_ppm": "(C)0.02",
      "pel_mgm3": "(C)0.2",
      "id": "methylene-bisphenyl-isocyanate-mdi",
      "url": "https://referencesource.org/workplace-exposure-limits/methylene-bisphenyl-isocyanate-mdi/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methylene bisphenyl isocyanate (MDI) | 101-68-8 | (C)0.02 | (C)0.2 | - |"
    },
    {
      "substance": "Methylene chloride",
      "cas_number": "75-09-2",
      "id": "methylene-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/methylene-chloride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Methylene chloride | 75-09-2 | - | ( 2 ) | - |"
    },
    {
      "substance": "Methylene chloride; dichloromethane (see also section 5202)",
      "pel_ppm": "25",
      "pel_mgm3": "87",
      "stel_ppm": "125",
      "stel_mgm3": "435",
      "id": "methylene-chloride-dichloromethane-see-also-section-5202",
      "url": "https://referencesource.org/workplace-exposure-limits/methylene-chloride-dichloromethane-see-also-section-5202/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75092 | | Methylene chloride; dichloromethane (see also section 5202) | 25 | 87 | | 125 | 435"
    },
    {
      "substance": "Metribuzin",
      "pel_mgm3": "5",
      "id": "metribuzin",
      "url": "https://referencesource.org/workplace-exposure-limits/metribuzin/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "21087649 | | Metribuzin | -- | 5"
    },
    {
      "substance": "Mevinphos; 2-carbomethoxyl-1-propen-2-yl dimethyl phosphate",
      "pel_ppm": "0.01",
      "pel_mgm3": "0.1",
      "stel_ppm": "0.03",
      "stel_mgm3": "0.3",
      "id": "mevinphos-2-carbomethoxyl-1-propen-2-yl-dimethyl-phosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/mevinphos-2-carbomethoxyl-1-propen-2-yl-dimethyl-phosphate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7786347 | S | Mevinphos; 2-carbomethoxyl-1-propen-2-yl dimethyl phosphate | 0.01 | 0.1 | | 0.03 | 0.3"
    },
    {
      "substance": "Mica (respirable dust)",
      "cas_number": "12001-26-2",
      "id": "mica-respirable-dust",
      "url": "https://referencesource.org/workplace-exposure-limits/mica-respirable-dust/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Mica (respirable dust) | 12001-26-2 | - | ( 3 ) | - |",
      "disagreements": []
    },
    {
      "substance": "Molybdenum (as Mo)",
      "cas_number": "7439-98-7",
      "id": "molybdenum-as-mo",
      "url": "https://referencesource.org/workplace-exposure-limits/molybdenum-as-mo/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Molybdenum (as Mo) | 7439-98-7 | - | - | - |"
    },
    {
      "substance": "Molybdenum, insoluble compounds, as Mo",
      "pel_mgm3": "0.5 (n)",
      "id": "molybdenum-insoluble-compounds-as-mo",
      "url": "https://referencesource.org/workplace-exposure-limits/molybdenum-insoluble-compounds-as-mo/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7439987 | | Molybdenum, insoluble compounds, as Mo | -- | 0.5 (n)"
    },
    {
      "substance": "Monocrotophos",
      "pel_mgm3": "0.25",
      "id": "monocrotophos",
      "url": "https://referencesource.org/workplace-exposure-limits/monocrotophos/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "6923224 | | Monocrotophos | -- | 0.25"
    },
    {
      "substance": "Monomethyl aniline",
      "cas_number": "100-61-8",
      "pel_ppm": "2",
      "pel_mgm3": "9",
      "id": "monomethyl-aniline",
      "url": "https://referencesource.org/workplace-exposure-limits/monomethyl-aniline/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Monomethyl aniline | 100-61-8 | 2 | 9 | X |"
    },
    {
      "substance": "Monomethylaniline; see N-Methylaniline",
      "id": "monomethylaniline-see-n-methylaniline",
      "url": "https://referencesource.org/workplace-exposure-limits/monomethylaniline-see-n-methylaniline/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "100618 | | Monomethylaniline; see N-Methylaniline"
    },
    {
      "substance": "Monomethylhydrazine; see Methyl hydrazine",
      "id": "monomethylhydrazine-see-methyl-hydrazine",
      "url": "https://referencesource.org/workplace-exposure-limits/monomethylhydrazine-see-methyl-hydrazine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "60344 | | Monomethylhydrazine; see Methyl hydrazine"
    },
    {
      "substance": "Morpholine",
      "cas_number": "110-91-8",
      "pel_ppm": "20",
      "pel_mgm3": "70",
      "id": "morpholine",
      "url": "https://referencesource.org/workplace-exposure-limits/morpholine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Morpholine | 110-91-8 | 20 | 70 | X |"
    },
    {
      "substance": "Morpholine; tetrahydro-4H-1, 4-oxazine",
      "pel_ppm": "20",
      "pel_mgm3": "70",
      "stel_ppm": "30",
      "stel_mgm3": "105",
      "id": "morpholine-tetrahydro-4h-1-4-oxazine",
      "url": "https://referencesource.org/workplace-exposure-limits/morpholine-tetrahydro-4h-1-4-oxazine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "110918 | S | Morpholine; tetrahydro-4H-1, 4-oxazine | 20 | 70 | | 30 | 105"
    },
    {
      "substance": "Muriatic acid; see Hydrogen chloride",
      "id": "muriatic-acid-see-hydrogen-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/muriatic-acid-see-hydrogen-chloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7647010 | | Muriatic acid; see Hydrogen chloride"
    },
    {
      "substance": "n-Amyl acetate",
      "cas_number": "628-63-7",
      "pel_ppm": "100",
      "pel_mgm3": "525",
      "id": "n-amyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/n-amyl-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "n-Amyl acetate | 628-63-7 | 100 | 525 | - |"
    },
    {
      "substance": "n-Amyl acetate; see Pentyl acetate",
      "id": "n-amyl-acetate-see-pentyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/n-amyl-acetate-see-pentyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "628637 | | n-Amyl acetate; see Pentyl acetate"
    },
    {
      "substance": "n-Butyl-acetate",
      "cas_number": "123-86-4",
      "pel_ppm": "150",
      "pel_mgm3": "710",
      "id": "n-butyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/n-butyl-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "n-Butyl-acetate | 123-86-4 | 150 | 710 | - |"
    },
    {
      "substance": "n-Butyl acetate",
      "pel_ppm": "150",
      "pel_mgm3": "710",
      "stel_ppm": "200",
      "stel_mgm3": "950",
      "id": "n-butyl-acetate-2",
      "url": "https://referencesource.org/workplace-exposure-limits/n-butyl-acetate-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "123864 | | n-Butyl acetate | 150 | 710 | | 200 | 950"
    },
    {
      "substance": "n-Butyl alcohol",
      "cas_number": "71-36-3",
      "pel_ppm": "100",
      "pel_mgm3": "300",
      "id": "n-butyl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/n-butyl-alcohol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "n-Butyl alcohol | 71-36-3 | 100 | 300 | - |"
    },
    {
      "substance": "n-Butyl alcohol; 1-butanol",
      "pel_ppm": "50",
      "pel_mgm3": "150",
      "ceiling": "C",
      "id": "n-butyl-alcohol-1-butanol",
      "url": "https://referencesource.org/workplace-exposure-limits/n-butyl-alcohol-1-butanol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "71363 | S | n-Butyl alcohol; 1-butanol | 50 | 150 | C"
    },
    {
      "substance": "n-Butyl glycidyl ether (BGE)",
      "cas_number": "2426-08-6",
      "pel_ppm": "50",
      "pel_mgm3": "270",
      "id": "n-butyl-glycidyl-ether-bge",
      "url": "https://referencesource.org/workplace-exposure-limits/n-butyl-glycidyl-ether-bge/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "n-Butyl glycidyl ether (BGE) | 2426-08-6 | 50 | 270 | - |"
    },
    {
      "substance": "n-Butyl glycidyl ether; BGE; 1-butoxy-2,3-epoxypropane",
      "pel_ppm": "25",
      "pel_mgm3": "135",
      "id": "n-butyl-glycidyl-ether-bge-1-butoxy-2-3-epoxypropane",
      "url": "https://referencesource.org/workplace-exposure-limits/n-butyl-glycidyl-ether-bge-1-butoxy-2-3-epoxypropane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "2426086 | | n-Butyl glycidyl ether; BGE; 1-butoxy-2,3-epoxypropane | 25 | 135"
    },
    {
      "substance": "n-Butyl lactate",
      "pel_ppm": "5",
      "pel_mgm3": "25",
      "id": "n-butyl-lactate",
      "url": "https://referencesource.org/workplace-exposure-limits/n-butyl-lactate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "138227 | | n-Butyl lactate | 5 | 25"
    },
    {
      "substance": "n-Butyl mercaptan",
      "pel_ppm": "0.5",
      "pel_mgm3": "1.5",
      "id": "n-butyl-mercaptan",
      "url": "https://referencesource.org/workplace-exposure-limits/n-butyl-mercaptan/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "109795 | | n-Butyl mercaptan | 0.5 | 1.5"
    },
    {
      "substance": "N-Ethylmorpholine",
      "cas_number": "100-74-3",
      "pel_ppm": "20",
      "pel_mgm3": "94",
      "id": "n-ethylmorpholine",
      "url": "https://referencesource.org/workplace-exposure-limits/n-ethylmorpholine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "N-Ethylmorpholine | 100-74-3 | 20 | 94 | X |"
    },
    {
      "substance": "N-Ethylmorpholine; 4-ethyl-1, 4-tetrahydrooxazine",
      "pel_ppm": "5",
      "pel_mgm3": "23",
      "id": "n-ethylmorpholine-4-ethyl-1-4-tetrahydrooxazine",
      "url": "https://referencesource.org/workplace-exposure-limits/n-ethylmorpholine-4-ethyl-1-4-tetrahydrooxazine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "100743 | S | N-Ethylmorpholine; 4-ethyl-1, 4-tetrahydrooxazine | 5 | 23"
    },
    {
      "substance": "n-Heptane",
      "pel_ppm": "400",
      "pel_mgm3": "1,600",
      "stel_ppm": "500",
      "stel_mgm3": "2000",
      "id": "n-heptane",
      "url": "https://referencesource.org/workplace-exposure-limits/n-heptane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "142825 | | n-Heptane | 400 | 1,600 | | 500 | 2000"
    },
    {
      "substance": "n-Hexane",
      "cas_number": "110-54-3",
      "pel_ppm": "500",
      "pel_mgm3": "1800",
      "id": "n-hexane",
      "url": "https://referencesource.org/workplace-exposure-limits/n-hexane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "n-Hexane | 110-54-3 | 500 | 1800 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "500",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "n-Hexane | 110-54-3 | 500 | 1800 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "50",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "110543 | S | n-Hexane | 50 | 180",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "1800",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "n-Hexane | 110-54-3 | 500 | 1800 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "180",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "110543 | S | n-Hexane | 50 | 180",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "N-isopropylaniline",
      "pel_ppm": "2",
      "pel_mgm3": "10",
      "id": "n-isopropylaniline",
      "url": "https://referencesource.org/workplace-exposure-limits/n-isopropylaniline/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "768525 | S | N-isopropylaniline | 2 | 10"
    },
    {
      "substance": "N-Methylaniline; monomethylaniline",
      "pel_ppm": "0.5",
      "pel_mgm3": "2",
      "id": "n-methylaniline-monomethylaniline",
      "url": "https://referencesource.org/workplace-exposure-limits/n-methylaniline-monomethylaniline/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "100618 | S | N-Methylaniline; monomethylaniline | 0.5 | 2"
    },
    {
      "substance": "N-Methylpyrrolidone (NMP)",
      "pel_ppm": "1",
      "pel_mgm3": "4",
      "id": "n-methylpyrrolidone-nmp",
      "url": "https://referencesource.org/workplace-exposure-limits/n-methylpyrrolidone-nmp/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "872504 | S | N-Methylpyrrolidone (NMP) | 1 | 4"
    },
    {
      "substance": "N,N-Dimethylaniline; dimethylphenylamine",
      "pel_ppm": "5",
      "pel_mgm3": "25",
      "stel_ppm": "10",
      "stel_mgm3": "50",
      "id": "n-n-dimethylaniline-dimethylphenylamine",
      "url": "https://referencesource.org/workplace-exposure-limits/n-n-dimethylaniline-dimethylphenylamine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "121697 | S | N,N-Dimethylaniline; dimethylphenylamine | 5 | 25 | | 10 | 50"
    },
    {
      "substance": "N,N-Dimethylnitrosamine; see N-Nitrosodimethylamine, Section 5209",
      "id": "n-n-dimethylnitrosamine-see-n-nitrosodimethylamine-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/n-n-dimethylnitrosamine-see-n-nitrosodimethylamine-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "62759 | | N,N-Dimethylnitrosamine; see N-Nitrosodimethylamine, Section 5209"
    },
    {
      "substance": "N-Nitrosodimethylamine, see Section 5209",
      "id": "n-nitrosodimethylamine-see-section-5209",
      "url": "https://referencesource.org/workplace-exposure-limits/n-nitrosodimethylamine-see-section-5209/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "62759 | | N-Nitrosodimethylamine, see Section 5209"
    },
    {
      "substance": "n-Propyl acetate",
      "cas_number": "109-60-4",
      "pel_ppm": "200",
      "pel_mgm3": "840",
      "id": "n-propyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/n-propyl-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "n-Propyl acetate | 109-60-4 | 200 | 840 | - |",
      "disagreements": []
    },
    {
      "substance": "n-Propyl alcohol",
      "cas_number": "71-23-8",
      "pel_ppm": "200",
      "pel_mgm3": "500",
      "id": "n-propyl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/n-propyl-alcohol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "n-Propyl alcohol | 71-23-8 | 200 | 500 | - |",
      "disagreements": []
    },
    {
      "substance": "n-Propyl nitrate",
      "cas_number": "627-13-4",
      "pel_ppm": "25",
      "pel_mgm3": "110",
      "id": "n-propyl-nitrate",
      "url": "https://referencesource.org/workplace-exposure-limits/n-propyl-nitrate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "n-Propyl nitrate | 627-13-4 | 25 | 110 | - |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "110",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "n-Propyl nitrate | 627-13-4 | 25 | 110 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "107",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "627134 | | n-Propyl nitrate | 25 | 107 | | 40 | 170",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Naled; o,o-dimethyl o-(1,2-dibromo-2,2-dichloroethyl) phosphate",
      "pel_mgm3": "3",
      "id": "naled-o-o-dimethyl-o-1-2-dibromo-2-2-dichloroethyl-phosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/naled-o-o-dimethyl-o-1-2-dibromo-2-2-dichloroethyl-phosphate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "300765 | S | Naled; o,o-dimethyl o-(1,2-dibromo-2,2-dichloroethyl) phosphate | -- | 3"
    },
    {
      "substance": "Naphtha (Coal tar)",
      "cas_number": "8030-30-6",
      "pel_ppm": "100",
      "pel_mgm3": "400",
      "id": "naphtha-coal-tar",
      "url": "https://referencesource.org/workplace-exposure-limits/naphtha-coal-tar/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Naphtha (Coal tar) | 8030-30-6 | 100 | 400 | - |"
    },
    {
      "substance": "Naphtha, coal tar",
      "pel_ppm": "100",
      "pel_mgm3": "400",
      "id": "naphtha-coal-tar-2",
      "url": "https://referencesource.org/workplace-exposure-limits/naphtha-coal-tar-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "8030317 | | Naphtha, coal tar | 100 | 400"
    },
    {
      "substance": "Naphthalene",
      "cas_number": "91-20-3",
      "pel_ppm": "10",
      "pel_mgm3": "50",
      "id": "naphthalene",
      "url": "https://referencesource.org/workplace-exposure-limits/naphthalene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Naphthalene | 91-20-3 | 10 | 50 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "10",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Naphthalene | 91-20-3 | 10 | 50 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "91203 | S | Naphthalene | 0.1 | 0.5",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "50",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Naphthalene | 91-20-3 | 10 | 50 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "91203 | S | Naphthalene | 0.1 | 0.5",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Naphthalene diisocyanate; NDI",
      "pel_ppm": "0.01",
      "pel_mgm3": "0.085",
      "ceiling": "C",
      "id": "naphthalene-diisocyanate-ndi",
      "url": "https://referencesource.org/workplace-exposure-limits/naphthalene-diisocyanate-ndi/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "25551284 | | Naphthalene diisocyanate; NDI | 0.01 | 0.085 | C"
    },
    {
      "substance": "Neon",
      "id": "neon",
      "url": "https://referencesource.org/workplace-exposure-limits/neon/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440019 | | Neon | (h)"
    },
    {
      "substance": "Nickel carbonyl (as Ni)",
      "cas_number": "13463-39-3",
      "pel_ppm": "0.001",
      "pel_mgm3": "0.007",
      "id": "nickel-carbonyl-as-ni",
      "url": "https://referencesource.org/workplace-exposure-limits/nickel-carbonyl-as-ni/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Nickel carbonyl (as Ni) | 13463-39-3 | 0.001 | 0.007 | - |"
    },
    {
      "substance": "Nickel carbonyl; Ni (CO) $4",
      "pel_ppm": "0.001",
      "pel_mgm3": "0.007",
      "id": "nickel-carbonyl-ni-co-4",
      "url": "https://referencesource.org/workplace-exposure-limits/nickel-carbonyl-ni-co-4/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "13463393 | | Nickel carbonyl; Ni (CO) $4 | 0.001 | 0.007"
    },
    {
      "substance": "Nickel, metal and insoluble compounds (as Ni)",
      "cas_number": "7440-02-0",
      "pel_mgm3": "1",
      "id": "nickel-metal-and-insoluble-compounds-as-ni",
      "url": "https://referencesource.org/workplace-exposure-limits/nickel-metal-and-insoluble-compounds-as-ni/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Nickel, metal and insoluble compounds (as Ni) | 7440-02-0 | - | 1 | - |"
    },
    {
      "substance": "Nickel metal, as Ni",
      "pel_mgm3": "0.5",
      "id": "nickel-metal-as-ni",
      "url": "https://referencesource.org/workplace-exposure-limits/nickel-metal-as-ni/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440020 | | Nickel metal, as Ni | -- | 0.5"
    },
    {
      "substance": "Nickel, soluble compounds (as Ni)",
      "cas_number": "7440-02-0",
      "pel_mgm3": "1",
      "id": "nickel-soluble-compounds-as-ni",
      "url": "https://referencesource.org/workplace-exposure-limits/nickel-soluble-compounds-as-ni/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Nickel, soluble compounds (as Ni) | 7440-02-0 | - | 1 | - |"
    },
    {
      "substance": "Nickel subsulfide",
      "pel_mgm3": ".05",
      "id": "nickel-subsulfide",
      "url": "https://referencesource.org/workplace-exposure-limits/nickel-subsulfide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "12035722 | | Nickel subsulfide | -- | .05"
    },
    {
      "substance": "Nicotine",
      "cas_number": "54-11-5",
      "pel_mgm3": "0.5",
      "id": "nicotine",
      "url": "https://referencesource.org/workplace-exposure-limits/nicotine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Nicotine | 54-11-5 | - | 0.5 | X |"
    },
    {
      "substance": "Nicotine; 1-methyl-2-(3-pyridyl)-pyrrolidine",
      "pel_ppm": "0.075",
      "pel_mgm3": "0.5",
      "id": "nicotine-1-methyl-2-3-pyridyl-pyrrolidine",
      "url": "https://referencesource.org/workplace-exposure-limits/nicotine-1-methyl-2-3-pyridyl-pyrrolidine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "54115 | S | Nicotine; 1-methyl-2-(3-pyridyl)-pyrrolidine | 0.075 | 0.5"
    },
    {
      "substance": "Nitrapyrin",
      "id": "nitrapyrin",
      "url": "https://referencesource.org/workplace-exposure-limits/nitrapyrin/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1929824 | | Nitrapyrin | --"
    },
    {
      "substance": "Nitric acid",
      "cas_number": "7697-37-2",
      "pel_ppm": "2",
      "pel_mgm3": "5",
      "id": "nitric-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/nitric-acid/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Nitric acid | 7697-37-2 | 2 | 5 | - |",
      "disagreements": []
    },
    {
      "substance": "Nitric oxide",
      "cas_number": "10102-43-9",
      "pel_ppm": "25",
      "pel_mgm3": "30",
      "id": "nitric-oxide",
      "url": "https://referencesource.org/workplace-exposure-limits/nitric-oxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Nitric oxide | 10102-43-9 | 25 | 30 | - |"
    },
    {
      "substance": "Nitric oxide; NO",
      "pel_ppm": "25",
      "pel_mgm3": "30",
      "id": "nitric-oxide-no",
      "url": "https://referencesource.org/workplace-exposure-limits/nitric-oxide-no/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "10102439 | | Nitric oxide; NO | 25 | 30"
    },
    {
      "substance": "Nitrobenzene",
      "cas_number": "98-95-3",
      "pel_ppm": "1",
      "pel_mgm3": "5",
      "id": "nitrobenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/nitrobenzene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Nitrobenzene | 98-95-3 | 1 | 5 | X |",
      "disagreements": []
    },
    {
      "substance": "Nitroethane",
      "cas_number": "79-24-3",
      "pel_ppm": "100",
      "pel_mgm3": "310",
      "id": "nitroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/nitroethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Nitroethane | 79-24-3 | 100 | 310 | - |",
      "disagreements": []
    },
    {
      "substance": "Nitrogen",
      "id": "nitrogen",
      "url": "https://referencesource.org/workplace-exposure-limits/nitrogen/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7727379 | | Nitrogen | (h) | --"
    },
    {
      "substance": "Nitrogen dioxide",
      "cas_number": "10102-44-0",
      "pel_ppm": "(C)5",
      "pel_mgm3": "(C)9",
      "id": "nitrogen-dioxide",
      "url": "https://referencesource.org/workplace-exposure-limits/nitrogen-dioxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Nitrogen dioxide | 10102-44-0 | (C)5 | (C)9 | - |",
      "disagreements": []
    },
    {
      "substance": "Nitrogen trifluoride",
      "cas_number": "7783-54-2",
      "pel_ppm": "10",
      "pel_mgm3": "29",
      "id": "nitrogen-trifluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/nitrogen-trifluoride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Nitrogen trifluoride | 7783-54-2 | 10 | 29 | - |",
      "disagreements": []
    },
    {
      "substance": "Nitroglycerin",
      "cas_number": "55-63-0",
      "pel_ppm": "(C)0.2",
      "pel_mgm3": "(C)2",
      "id": "nitroglycerin",
      "url": "https://referencesource.org/workplace-exposure-limits/nitroglycerin/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Nitroglycerin | 55-63-0 | (C)0.2 | (C)2 | X |",
      "disagreements": []
    },
    {
      "substance": "Nitromethane",
      "cas_number": "75-52-5",
      "pel_ppm": "100",
      "pel_mgm3": "250",
      "id": "nitromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/nitromethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Nitromethane | 75-52-5 | 100 | 250 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "100",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Nitromethane | 75-52-5 | 100 | 250 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "2",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "75525 | | Nitromethane | 2 | 5",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "250",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Nitromethane | 75-52-5 | 100 | 250 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "75525 | | Nitromethane | 2 | 5",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Nitrotrichloromethane; see Chloropicrin",
      "id": "nitrotrichloromethane-see-chloropicrin",
      "url": "https://referencesource.org/workplace-exposure-limits/nitrotrichloromethane-see-chloropicrin/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "76062 | | Nitrotrichloromethane; see Chloropicrin"
    },
    {
      "substance": "Nitrous oxide",
      "pel_ppm": "50",
      "pel_mgm3": "90",
      "id": "nitrous-oxide",
      "url": "https://referencesource.org/workplace-exposure-limits/nitrous-oxide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "0024972 | | Nitrous oxide | 50 | 90"
    },
    {
      "substance": "Nonane",
      "pel_ppm": "200",
      "pel_mgm3": "1,050",
      "id": "nonane",
      "url": "https://referencesource.org/workplace-exposure-limits/nonane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "111842 | | Nonane | 200 | 1,050"
    },
    {
      "substance": "o-Chlorobenzylidene malononitrile",
      "cas_number": "2698-41-1",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.4",
      "id": "o-chlorobenzylidene-malononitrile",
      "url": "https://referencesource.org/workplace-exposure-limits/o-chlorobenzylidene-malononitrile/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "o-Chlorobenzylidene malononitrile | 2698-41-1 | 0.05 | 0.4 | - |"
    },
    {
      "substance": "o-Chlorobenzylidene malononitrile; OCBM",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.4",
      "ceiling": "C",
      "id": "o-chlorobenzylidene-malononitrile-ocbm",
      "url": "https://referencesource.org/workplace-exposure-limits/o-chlorobenzylidene-malononitrile-ocbm/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "2698411 | S | o-Chlorobenzylidene malononitrile; OCBM | 0.05 | 0.4 | C"
    },
    {
      "substance": "o-Chlorostyrene",
      "pel_ppm": "50",
      "pel_mgm3": "285",
      "stel_ppm": "75",
      "stel_mgm3": "428",
      "id": "o-chlorostyrene",
      "url": "https://referencesource.org/workplace-exposure-limits/o-chlorostyrene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "2039874 | | o-Chlorostyrene | 50 | 285 | | 75 | 428"
    },
    {
      "substance": "o-Chlorotoluene",
      "pel_ppm": "50",
      "pel_mgm3": "250",
      "id": "o-chlorotoluene",
      "url": "https://referencesource.org/workplace-exposure-limits/o-chlorotoluene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "95498 | S | o-Chlorotoluene | 50 | 250"
    },
    {
      "substance": "o-Dichlorobenzene",
      "cas_number": "95-50-1",
      "pel_ppm": "(C)50",
      "pel_mgm3": "(C)300",
      "id": "o-dichlorobenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/o-dichlorobenzene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "o-Dichlorobenzene | 95-50-1 | (C)50 | (C)300 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "(C)50",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "o-Dichlorobenzene | 95-50-1 | (C)50 | (C)300 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "25",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "95501 | S | o-Dichlorobenzene | 25 | 150 | 50 ppm",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "(C)300",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "o-Dichlorobenzene | 95-50-1 | (C)50 | (C)300 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "150",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "95501 | S | o-Dichlorobenzene | 25 | 150 | 50 ppm",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "o-isomer",
      "cas_number": "88-72-2",
      "id": "o-isomer",
      "url": "https://referencesource.org/workplace-exposure-limits/o-isomer/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "o-isomer | 88-72-2 | - | - | - |"
    },
    {
      "substance": "o-Methylaniline; see o-Toluidine",
      "id": "o-methylaniline-see-o-toluidine",
      "url": "https://referencesource.org/workplace-exposure-limits/o-methylaniline-see-o-toluidine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "95534 | | o-Methylaniline; see o-Toluidine"
    },
    {
      "substance": "o-Methylcyclohexanone",
      "cas_number": "583-60-8",
      "pel_ppm": "100",
      "pel_mgm3": "460",
      "id": "o-methylcyclohexanone",
      "url": "https://referencesource.org/workplace-exposure-limits/o-methylcyclohexanone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "o-Methylcyclohexanone | 583-60-8 | 100 | 460 | X |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "100",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "o-Methylcyclohexanone | 583-60-8 | 100 | 460 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "50",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "583608 | S | o-Methylcyclohexanone | 50 | 230 | | 75 | 345",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "460",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "o-Methylcyclohexanone | 583-60-8 | 100 | 460 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "230",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "583608 | S | o-Methylcyclohexanone | 50 | 230 | | 75 | 345",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "o,o-Dimethyl o-(1,2-dibromo-2,2-dichloroethyl) phosphate; see Naled",
      "id": "o-o-dimethyl-o-1-2-dibromo-2-2-dichloroethyl-phosphate-see-naled",
      "url": "https://referencesource.org/workplace-exposure-limits/o-o-dimethyl-o-1-2-dibromo-2-2-dichloroethyl-phosphate-see-naled/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "300765 | | o,o-Dimethyl o-(1,2-dibromo-2,2-dichloroethyl) phosphate; see Naled"
    },
    {
      "substance": "o-sec-Butylphenol",
      "pel_ppm": "5",
      "pel_mgm3": "30",
      "id": "o-sec-butylphenol",
      "url": "https://referencesource.org/workplace-exposure-limits/o-sec-butylphenol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "89725 | S | o-sec-Butylphenol | 5 | 30"
    },
    {
      "substance": "o-Toluidine",
      "cas_number": "95-53-4",
      "pel_ppm": "5",
      "pel_mgm3": "22",
      "id": "o-toluidine",
      "url": "https://referencesource.org/workplace-exposure-limits/o-toluidine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "o-Toluidine | 95-53-4 | 5 | 22 | X |"
    },
    {
      "substance": "o-Toluidine; o-methylaniline",
      "pel_ppm": "2",
      "pel_mgm3": "9",
      "id": "o-toluidine-o-methylaniline",
      "url": "https://referencesource.org/workplace-exposure-limits/o-toluidine-o-methylaniline/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "95534 | S | o-Toluidine; o-methylaniline | 2 | 9"
    },
    {
      "substance": "Octachloronaphthalene",
      "cas_number": "2234-13-1",
      "pel_mgm3": "0.1",
      "id": "octachloronaphthalene",
      "url": "https://referencesource.org/workplace-exposure-limits/octachloronaphthalene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Octachloronaphthalene | 2234-13-1 | - | 0.1 | X |",
      "disagreements": []
    },
    {
      "substance": "Octane",
      "cas_number": "111-65-9",
      "pel_ppm": "500",
      "pel_mgm3": "2350",
      "id": "octane",
      "url": "https://referencesource.org/workplace-exposure-limits/octane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Octane | 111-65-9 | 500 | 2350 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "500",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Octane | 111-65-9 | 500 | 2350 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "300",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "111659 | | Octane | 300 | 1,450 | | 375 | 1800",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "2350",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Octane | 111-65-9 | 500 | 2350 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1,450",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "111659 | | Octane | 300 | 1,450 | | 375 | 1800",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Oil (mineral) mist, particulate",
      "pel_mgm3": "(5) (l)",
      "id": "oil-mineral-mist-particulate",
      "url": "https://referencesource.org/workplace-exposure-limits/oil-mineral-mist-particulate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "8012951 | | Oil (mineral) mist, particulate | -- | (5) (l)"
    },
    {
      "substance": "Oil mist, mineral",
      "cas_number": "8012-95-1",
      "pel_mgm3": "5",
      "id": "oil-mist-mineral",
      "url": "https://referencesource.org/workplace-exposure-limits/oil-mist-mineral/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Oil mist, mineral | 8012-95-1 | - | 5 | - |"
    },
    {
      "substance": "(ortho)",
      "cas_number": "528-29-0",
      "id": "ortho",
      "url": "https://referencesource.org/workplace-exposure-limits/ortho/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "(ortho) | 528-29-0 | - | - | - |"
    },
    {
      "substance": "Osmium tetroxide (as Os)",
      "cas_number": "20816-12-0",
      "pel_mgm3": "0.002",
      "id": "osmium-tetroxide-as-os",
      "url": "https://referencesource.org/workplace-exposure-limits/osmium-tetroxide-as-os/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Osmium tetroxide (as Os) | 20816-12-0 | - | 0.002 | - |"
    },
    {
      "substance": "Osmium tetroxide, as Os",
      "pel_ppm": "0.0002",
      "pel_mgm3": "0.002",
      "stel_ppm": "0.0006",
      "stel_mgm3": "0.006",
      "id": "osmium-tetroxide-as-os-2",
      "url": "https://referencesource.org/workplace-exposure-limits/osmium-tetroxide-as-os-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "20816120 | | Osmium tetroxide, as Os | 0.0002 | 0.002 | | 0.0006 | 0.006"
    },
    {
      "substance": "Oxalic acid",
      "cas_number": "144-62-7",
      "pel_mgm3": "1",
      "id": "oxalic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/oxalic-acid/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Oxalic acid | 144-62-7 | - | 1 | - |",
      "disagreements": []
    },
    {
      "substance": "Oxygen difluoride",
      "cas_number": "7783-41-7",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.1",
      "id": "oxygen-difluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/oxygen-difluoride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Oxygen difluoride | 7783-41-7 | 0.05 | 0.1 | - |",
      "disagreements": []
    },
    {
      "substance": "Ozone",
      "cas_number": "10028-15-6",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.2",
      "id": "ozone",
      "url": "https://referencesource.org/workplace-exposure-limits/ozone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ozone | 10028-15-6 | 0.1 | 0.2 | - |",
      "disagreements": []
    },
    {
      "substance": "p-Dichlorobenzene",
      "cas_number": "106-46-7",
      "pel_ppm": "75",
      "pel_mgm3": "450",
      "id": "p-dichlorobenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/p-dichlorobenzene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "p-Dichlorobenzene | 106-46-7 | 75 | 450 | - |"
    },
    {
      "substance": "p-Dichlorobenzene; 1,4-dichlorobenzene",
      "pel_ppm": "10",
      "pel_mgm3": "60",
      "ceiling": "200 ppm",
      "stel_ppm": "110",
      "stel_mgm3": "675",
      "id": "p-dichlorobenzene-1-4-dichlorobenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/p-dichlorobenzene-1-4-dichlorobenzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106467 | | p-Dichlorobenzene; 1,4-dichlorobenzene | 10 | 60 | 200 ppm | 110 | 675"
    },
    {
      "substance": "p-Dihydroxybenzene; see Hydroquinone",
      "id": "p-dihydroxybenzene-see-hydroquinone",
      "url": "https://referencesource.org/workplace-exposure-limits/p-dihydroxybenzene-see-hydroquinone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "123319 | | p-Dihydroxybenzene; see Hydroquinone"
    },
    {
      "substance": "p-Dioxane;",
      "id": "p-dioxane",
      "url": "https://referencesource.org/workplace-exposure-limits/p-dioxane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "123911 | S | p-Dioxane;"
    },
    {
      "substance": "p-isomer",
      "cas_number": "99-99-0",
      "id": "p-isomer",
      "url": "https://referencesource.org/workplace-exposure-limits/p-isomer/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "p-isomer | 99-99-0 | - | - | - |"
    },
    {
      "substance": "p-Nitroaniline",
      "cas_number": "100-01-6",
      "pel_ppm": "1",
      "pel_mgm3": "6",
      "id": "p-nitroaniline",
      "url": "https://referencesource.org/workplace-exposure-limits/p-nitroaniline/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "p-Nitroaniline | 100-01-6 | 1 | 6 | X |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "6",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "p-Nitroaniline | 100-01-6 | 1 | 6 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "3",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "100016 | S | p-Nitroaniline | -- | 3",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "p-Nitrochlorobenzene",
      "cas_number": "100-00-5",
      "pel_mgm3": "1",
      "id": "p-nitrochlorobenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/p-nitrochlorobenzene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "p-Nitrochlorobenzene | 100-00-5 | - | 1 | X |"
    },
    {
      "substance": "p-Nitrochlorobenzene; 1-chloro-4-nitrobenzene",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.64",
      "id": "p-nitrochlorobenzene-1-chloro-4-nitrobenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/p-nitrochlorobenzene-1-chloro-4-nitrobenzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "100005 | S | p-Nitrochlorobenzene; 1-chloro-4-nitrobenzene | 0.1 | 0.64"
    },
    {
      "substance": "p-Phenylene diamine",
      "cas_number": "106-50-3",
      "pel_mgm3": "0.1",
      "id": "p-phenylene-diamine",
      "url": "https://referencesource.org/workplace-exposure-limits/p-phenylene-diamine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "p-Phenylene diamine | 106-50-3 | - | 0.1 | X |"
    },
    {
      "substance": "p-Phenylenediamine",
      "pel_mgm3": "0.1",
      "id": "p-phenylenediamine",
      "url": "https://referencesource.org/workplace-exposure-limits/p-phenylenediamine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106503 | S | p-Phenylenediamine | -- | 0.1"
    },
    {
      "substance": "p-tert-Butyltoluene",
      "cas_number": "98-51-1",
      "pel_ppm": "10",
      "pel_mgm3": "60",
      "id": "p-tert-butyltoluene",
      "url": "https://referencesource.org/workplace-exposure-limits/p-tert-butyltoluene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "p-tert-Butyltoluene | 98-51-1 | 10 | 60 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "10",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "p-tert-Butyltoluene | 98-51-1 | 10 | 60 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "98511 | | p-tert-Butyltoluene | 1 | 6.1 | | 20 | 120",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "60",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "p-tert-Butyltoluene | 98-51-1 | 10 | 60 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "6.1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "98511 | | p-tert-Butyltoluene | 1 | 6.1 | | 20 | 120",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "p-Toluidine",
      "pel_ppm": "2",
      "pel_mgm3": "9",
      "id": "p-toluidine",
      "url": "https://referencesource.org/workplace-exposure-limits/p-toluidine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106490 | S | p-Toluidine | 2 | 9"
    },
    {
      "substance": "(para)",
      "cas_number": "100-25-4",
      "id": "para",
      "url": "https://referencesource.org/workplace-exposure-limits/para/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "(para) | 100-25-4 | - | - | - |"
    },
    {
      "substance": "Paraffin wax fume",
      "pel_mgm3": "2",
      "id": "paraffin-wax-fume",
      "url": "https://referencesource.org/workplace-exposure-limits/paraffin-wax-fume/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "8002742 | | Paraffin wax fume | -- | 2"
    },
    {
      "substance": "Parathion",
      "cas_number": "56-38-2",
      "pel_mgm3": "0.1",
      "id": "parathion",
      "url": "https://referencesource.org/workplace-exposure-limits/parathion/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Parathion | 56-38-2 | - | 0.1 | X |"
    },
    {
      "substance": "Parathion; o,o-diethyl o-(p-nitrophenyl) phosphorothioate",
      "pel_mgm3": "0.1",
      "id": "parathion-o-o-diethyl-o-p-nitrophenyl-phosphorothioate",
      "url": "https://referencesource.org/workplace-exposure-limits/parathion-o-o-diethyl-o-p-nitrophenyl-phosphorothioate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "56382 | S | Parathion; o,o-diethyl o-(p-nitrophenyl) phosphorothioate | -- | 0.1"
    },
    {
      "substance": "PCP; see Pentachlorophenol",
      "id": "pcp-see-pentachlorophenol",
      "url": "https://referencesource.org/workplace-exposure-limits/pcp-see-pentachlorophenol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "87865 | S | PCP; see Pentachlorophenol"
    },
    {
      "substance": "Pentaborane",
      "cas_number": "19624-22-7",
      "pel_ppm": "0.005",
      "pel_mgm3": "0.01",
      "id": "pentaborane",
      "url": "https://referencesource.org/workplace-exposure-limits/pentaborane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Pentaborane | 19624-22-7 | 0.005 | 0.01 | - |",
      "disagreements": []
    },
    {
      "substance": "Pentachloronaphthalene",
      "cas_number": "1321-64-8",
      "pel_mgm3": "0.5",
      "id": "pentachloronaphthalene",
      "url": "https://referencesource.org/workplace-exposure-limits/pentachloronaphthalene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Pentachloronaphthalene | 1321-64-8 | - | 0.5 | X |",
      "disagreements": []
    },
    {
      "substance": "Pentachlorophenol",
      "cas_number": "87-86-5",
      "pel_mgm3": "0.5",
      "id": "pentachlorophenol",
      "url": "https://referencesource.org/workplace-exposure-limits/pentachlorophenol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Pentachlorophenol | 87-86-5 | - | 0.5 | X |"
    },
    {
      "substance": "Pentachlorophenol; PCP",
      "pel_mgm3": "0.5",
      "id": "pentachlorophenol-pcp",
      "url": "https://referencesource.org/workplace-exposure-limits/pentachlorophenol-pcp/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "87865 | S | Pentachlorophenol; PCP | -- | 0.5"
    },
    {
      "substance": "Pentaerythritol",
      "cas_number": "115-77-5",
      "id": "pentaerythritol",
      "url": "https://referencesource.org/workplace-exposure-limits/pentaerythritol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Pentaerythritol | 115-77-5 | - | - | - |"
    },
    {
      "substance": "Pentaerythritol; tetrakis-(hydroxymethyl)methane; tetra-methylolmethane; see Particulates not otherwise regulated",
      "id": "pentaerythritol-tetrakis-hydroxymethyl-methane-tetra-methylolmethane-see-particu",
      "url": "https://referencesource.org/workplace-exposure-limits/pentaerythritol-tetrakis-hydroxymethyl-methane-tetra-methylolmethane-see-particu/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "115775 | | Pentaerythritol; tetrakis-(hydroxymethyl)methane; tetra-methylolmethane; see Particulates not otherwise regulated"
    },
    {
      "substance": "Pentane",
      "cas_number": "109-66-0",
      "pel_ppm": "1000",
      "pel_mgm3": "2950",
      "id": "pentane",
      "url": "https://referencesource.org/workplace-exposure-limits/pentane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Pentane | 109-66-0 | 1000 | 2950 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "1000",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Pentane | 109-66-0 | 1000 | 2950 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "600",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "109660 | | Pentane | 600 | 1,800",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "2950",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Pentane | 109-66-0 | 1000 | 2950 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1,800",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "109660 | | Pentane | 600 | 1,800",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Perchloroethane; see Hexachloroethane",
      "id": "perchloroethane-see-hexachloroethane",
      "url": "https://referencesource.org/workplace-exposure-limits/perchloroethane-see-hexachloroethane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "67721 | | Perchloroethane; see Hexachloroethane"
    },
    {
      "substance": "Perchloroethylene",
      "pel_ppm": "25",
      "pel_mgm3": "170",
      "ceiling": "300 ppm",
      "stel_ppm": "100",
      "stel_mgm3": "685",
      "id": "perchloroethylene",
      "url": "https://referencesource.org/workplace-exposure-limits/perchloroethylene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "127184 | | Perchloroethylene | 25 | 170 | 300 ppm | 100 | 685"
    },
    {
      "substance": "Perchloroethylene (Tetrachloroethylene)",
      "cas_number": "127-18-4",
      "id": "perchloroethylene-tetrachloroethylene",
      "url": "https://referencesource.org/workplace-exposure-limits/perchloroethylene-tetrachloroethylene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Perchloroethylene (Tetrachloroethylene) | 127-18-4 | - | ( 2 ) | - |"
    },
    {
      "substance": "Perchloromethyl mercaptan",
      "cas_number": "594-42-3",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.8",
      "id": "perchloromethyl-mercaptan",
      "url": "https://referencesource.org/workplace-exposure-limits/perchloromethyl-mercaptan/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Perchloromethyl mercaptan | 594-42-3 | 0.1 | 0.8 | - |"
    },
    {
      "substance": "Perchloromethyl mercaptan; trichloromethanethiol",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.8",
      "id": "perchloromethyl-mercaptan-trichloromethanethiol",
      "url": "https://referencesource.org/workplace-exposure-limits/perchloromethyl-mercaptan-trichloromethanethiol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "594423 | | Perchloromethyl mercaptan; trichloromethanethiol | 0.1 | 0.8"
    },
    {
      "substance": "Perchloryl fluoride",
      "cas_number": "7616-94-6",
      "pel_ppm": "3",
      "pel_mgm3": "13.5",
      "id": "perchloryl-fluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/perchloryl-fluoride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Perchloryl fluoride | 7616-94-6 | 3 | 13.5 | - |"
    },
    {
      "substance": "Perchloryl fluoride; C10 $3 F",
      "pel_ppm": "3",
      "pel_mgm3": "14",
      "stel_ppm": "6",
      "stel_mgm3": "28",
      "id": "perchloryl-fluoride-c10-3-f",
      "url": "https://referencesource.org/workplace-exposure-limits/perchloryl-fluoride-c10-3-f/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7616946 | | Perchloryl fluoride; C10 $3 F | 3 | 14 | | 6 | 28"
    },
    {
      "substance": "Perfluoroisobutylene",
      "pel_ppm": "0.01",
      "pel_mgm3": "0.082",
      "ceiling": "C",
      "id": "perfluoroisobutylene",
      "url": "https://referencesource.org/workplace-exposure-limits/perfluoroisobutylene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "382218 | | Perfluoroisobutylene | 0.01 | 0.082 | C"
    },
    {
      "substance": "Phenol",
      "cas_number": "108-95-2",
      "pel_ppm": "5",
      "pel_mgm3": "19",
      "id": "phenol",
      "url": "https://referencesource.org/workplace-exposure-limits/phenol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Phenol | 108-95-2 | 5 | 19 | X |",
      "disagreements": []
    },
    {
      "substance": "Phenothiazine; dibenzothiazine",
      "pel_mgm3": "5",
      "id": "phenothiazine-dibenzothiazine",
      "url": "https://referencesource.org/workplace-exposure-limits/phenothiazine-dibenzothiazine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "92842 | S | Phenothiazine; dibenzothiazine | -- | 5"
    },
    {
      "substance": "Phenyl ether, vapor",
      "cas_number": "101-84-8",
      "pel_ppm": "1",
      "pel_mgm3": "7",
      "id": "phenyl-ether-vapor",
      "url": "https://referencesource.org/workplace-exposure-limits/phenyl-ether-vapor/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Phenyl ether, vapor | 101-84-8 | 1 | 7 | - |",
      "disagreements": []
    },
    {
      "substance": "Phenyl glycidyl ether (PGE)",
      "cas_number": "122-60-1",
      "pel_ppm": "10",
      "pel_mgm3": "60",
      "id": "phenyl-glycidyl-ether-pge",
      "url": "https://referencesource.org/workplace-exposure-limits/phenyl-glycidyl-ether-pge/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Phenyl glycidyl ether (PGE) | 122-60-1 | 10 | 60 | - |"
    },
    {
      "substance": "Phenyl glycidyl ether, PGE; 1,2-epoxy-3-phenoxypropane",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.6",
      "id": "phenyl-glycidyl-ether-pge-1-2-epoxy-3-phenoxypropane",
      "url": "https://referencesource.org/workplace-exposure-limits/phenyl-glycidyl-ether-pge-1-2-epoxy-3-phenoxypropane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "122601 | S | Phenyl glycidyl ether, PGE; 1,2-epoxy-3-phenoxypropane | 0.1 | 0.6"
    },
    {
      "substance": "Phenyl mercaptan",
      "pel_ppm": "0.5",
      "pel_mgm3": "2",
      "id": "phenyl-mercaptan",
      "url": "https://referencesource.org/workplace-exposure-limits/phenyl-mercaptan/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108985 | | Phenyl mercaptan | 0.5 | 2"
    },
    {
      "substance": "Phenylethylene; see Styrene",
      "id": "phenylethylene-see-styrene",
      "url": "https://referencesource.org/workplace-exposure-limits/phenylethylene-see-styrene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "100425 | | Phenylethylene; see Styrene"
    },
    {
      "substance": "Phenylhydrazine",
      "cas_number": "100-63-0",
      "pel_ppm": "5",
      "pel_mgm3": "22",
      "id": "phenylhydrazine",
      "url": "https://referencesource.org/workplace-exposure-limits/phenylhydrazine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Phenylhydrazine | 100-63-0 | 5 | 22 | X |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "22",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Phenylhydrazine | 100-63-0 | 5 | 22 | X |",
              "as_of": "2026-08-05"
            },
            {
              "value": "20",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "100630 | S | Phenylhydrazine | 5 | 20 | | 10 | 45",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Phenylphosphine",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.25",
      "ceiling": "C",
      "id": "phenylphosphine",
      "url": "https://referencesource.org/workplace-exposure-limits/phenylphosphine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "638211 | | Phenylphosphine | 0.05 | 0.25 | C"
    },
    {
      "substance": "Phorate; o,o-diethyl S-(ethylthio)methyl phosphorodithioate",
      "pel_mgm3": "0.05",
      "stel_mgm3": "0.2",
      "id": "phorate-o-o-diethyl-s-ethylthio-methyl-phosphorodithioate",
      "url": "https://referencesource.org/workplace-exposure-limits/phorate-o-o-diethyl-s-ethylthio-methyl-phosphorodithioate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "298022 | S | Phorate; o,o-diethyl S-(ethylthio)methyl phosphorodithioate | -- | 0.05 | | -- | 0.2"
    },
    {
      "substance": "Phosdrin (Mevinphos)",
      "cas_number": "7786-34-7",
      "pel_mgm3": "0.1",
      "id": "phosdrin-mevinphos",
      "url": "https://referencesource.org/workplace-exposure-limits/phosdrin-mevinphos/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Phosdrin (Mevinphos) | 7786-34-7 | - | 0.1 | X |"
    },
    {
      "substance": "Phosgene (Carbonyl chloride)",
      "cas_number": "75-44-5",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.4",
      "id": "phosgene-carbonyl-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/phosgene-carbonyl-chloride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Phosgene (Carbonyl chloride) | 75-44-5 | 0.1 | 0.4 | - |"
    },
    {
      "substance": "Phosgene; carbonyl chloride; COCl $2",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.4",
      "id": "phosgene-carbonyl-chloride-cocl-2",
      "url": "https://referencesource.org/workplace-exposure-limits/phosgene-carbonyl-chloride-cocl-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75445 | | Phosgene; carbonyl chloride; COCl $2 | 0.1 | 0.4"
    },
    {
      "substance": "Phosphine",
      "cas_number": "7803-51-2",
      "pel_ppm": "0.3",
      "pel_mgm3": "0.4",
      "id": "phosphine",
      "url": "https://referencesource.org/workplace-exposure-limits/phosphine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Phosphine | 7803-51-2 | 0.3 | 0.4 | - |"
    },
    {
      "substance": "Phosphine; PH $3",
      "pel_ppm": "0.3",
      "pel_mgm3": "0.4",
      "stel_ppm": "1",
      "stel_mgm3": "1",
      "id": "phosphine-ph-3",
      "url": "https://referencesource.org/workplace-exposure-limits/phosphine-ph-3/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7803512 | | Phosphine; PH $3 | 0.3 | 0.4 | | 1 | 1"
    },
    {
      "substance": "Phosphoric acid",
      "cas_number": "7664-38-2",
      "pel_mgm3": "1",
      "id": "phosphoric-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/phosphoric-acid/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Phosphoric acid | 7664-38-2 | - | 1 | - |",
      "disagreements": []
    },
    {
      "substance": "Phosphorus oxychloride",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.6",
      "id": "phosphorus-oxychloride",
      "url": "https://referencesource.org/workplace-exposure-limits/phosphorus-oxychloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "10025873 | | Phosphorus oxychloride | 0.1 | 0.6"
    },
    {
      "substance": "Phosphorus pentachloride",
      "cas_number": "10026-13-8",
      "pel_mgm3": "1",
      "id": "phosphorus-pentachloride",
      "url": "https://referencesource.org/workplace-exposure-limits/phosphorus-pentachloride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Phosphorus pentachloride | 10026-13-8 | - | 1 | - |",
      "disagreements": []
    },
    {
      "substance": "Phosphorus pentasulfide",
      "cas_number": "1314-80-3",
      "pel_mgm3": "1",
      "id": "phosphorus-pentasulfide",
      "url": "https://referencesource.org/workplace-exposure-limits/phosphorus-pentasulfide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Phosphorus pentasulfide | 1314-80-3 | - | 1 | - |"
    },
    {
      "substance": "Phosphorus pentasulfide; P $2 S $5",
      "pel_mgm3": "1",
      "stel_mgm3": "3",
      "id": "phosphorus-pentasulfide-p-2-s-5",
      "url": "https://referencesource.org/workplace-exposure-limits/phosphorus-pentasulfide-p-2-s-5/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1314803 | | Phosphorus pentasulfide; P $2 S $5 | -- | 1 | | -- | 3"
    },
    {
      "substance": "Phosphorus trichloride",
      "cas_number": "7719-12-2",
      "pel_ppm": "0.5",
      "pel_mgm3": "3",
      "id": "phosphorus-trichloride",
      "url": "https://referencesource.org/workplace-exposure-limits/phosphorus-trichloride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Phosphorus trichloride | 7719-12-2 | 0.5 | 3 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "0.5",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Phosphorus trichloride | 7719-12-2 | 0.5 | 3 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.2",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7719122 | | Phosphorus trichloride | 0.2 | 1.5 | | 0.5 | 3",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "3",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Phosphorus trichloride | 7719-12-2 | 0.5 | 3 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1.5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7719122 | | Phosphorus trichloride | 0.2 | 1.5 | | 0.5 | 3",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Phosphorus (yellow)",
      "cas_number": "7723-14-0",
      "pel_mgm3": "0.1",
      "id": "phosphorus-yellow",
      "url": "https://referencesource.org/workplace-exposure-limits/phosphorus-yellow/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Phosphorus (yellow) | 7723-14-0 | - | 0.1 | - |"
    },
    {
      "substance": "Phosphorus, yellow",
      "pel_mgm3": "0.1",
      "id": "phosphorus-yellow-2",
      "url": "https://referencesource.org/workplace-exposure-limits/phosphorus-yellow-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7723140 | | Phosphorus, yellow | -- | 0.1"
    },
    {
      "substance": "Phthalic anhydride",
      "cas_number": "85-44-9",
      "pel_ppm": "2",
      "pel_mgm3": "12",
      "id": "phthalic-anhydride",
      "url": "https://referencesource.org/workplace-exposure-limits/phthalic-anhydride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Phthalic anhydride | 85-44-9 | 2 | 12 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "2",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Phthalic anhydride | 85-44-9 | 2 | 12 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "85449 | | Phthalic anhydride | 1 | 6",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "12",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Phthalic anhydride | 85-44-9 | 2 | 12 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "6",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "85449 | | Phthalic anhydride | 1 | 6",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Picloram",
      "cas_number": "1918-02-1",
      "id": "picloram",
      "url": "https://referencesource.org/workplace-exposure-limits/picloram/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Picloram | 1918-02-1 | - | - | - |",
      "disagreements": []
    },
    {
      "substance": "Picric acid",
      "cas_number": "88-89-1",
      "pel_mgm3": "0.1",
      "id": "picric-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/picric-acid/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Picric acid | 88-89-1 | - | 0.1 | X |"
    },
    {
      "substance": "Picric acid; 2,4,6-trinitrophenol",
      "pel_mgm3": "0.1",
      "id": "picric-acid-2-4-6-trinitrophenol",
      "url": "https://referencesource.org/workplace-exposure-limits/picric-acid-2-4-6-trinitrophenol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "88891 | S | Picric acid; 2,4,6-trinitrophenol | -- | 0.1"
    },
    {
      "substance": "Pindone (2-Pivalyl-1,3-indandione)",
      "cas_number": "83-26-1",
      "pel_mgm3": "0.1",
      "id": "pindone-2-pivalyl-1-3-indandione",
      "url": "https://referencesource.org/workplace-exposure-limits/pindone-2-pivalyl-1-3-indandione/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Pindone (2-Pivalyl-1,3-indandione) | 83-26-1 | - | 0.1 | - |"
    },
    {
      "substance": "Pindone; 2-pivalyl-1, 3-indandione",
      "pel_mgm3": "0.1",
      "id": "pindone-2-pivalyl-1-3-indandione-2",
      "url": "https://referencesource.org/workplace-exposure-limits/pindone-2-pivalyl-1-3-indandione-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "83261 | | Pindone; 2-pivalyl-1, 3-indandione | | 0.1"
    },
    {
      "substance": "Piperazine dihydrochloride",
      "pel_mgm3": "5",
      "id": "piperazine-dihydrochloride",
      "url": "https://referencesource.org/workplace-exposure-limits/piperazine-dihydrochloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "142643 | | Piperazine dihydrochloride | -- | 5"
    },
    {
      "substance": "Plaster of Paris",
      "cas_number": "26499-65-0",
      "id": "plaster-of-paris",
      "url": "https://referencesource.org/workplace-exposure-limits/plaster-of-paris/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Plaster of Paris | 26499-65-0 | - | - | - |"
    },
    {
      "substance": "Plaster of Paris; calcium sulfate hemihydrate; see Particulates not otherwise regulated",
      "id": "plaster-of-paris-calcium-sulfate-hemihydrate-see-particulates-not-otherwise-regu",
      "url": "https://referencesource.org/workplace-exposure-limits/plaster-of-paris-calcium-sulfate-hemihydrate-see-particulates-not-otherwise-regu/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "26499650 | | Plaster of Paris; calcium sulfate hemihydrate; see Particulates not otherwise regulated"
    },
    {
      "substance": "Platinum (as Pt)",
      "cas_number": "7440-06-4",
      "id": "platinum-as-pt",
      "url": "https://referencesource.org/workplace-exposure-limits/platinum-as-pt/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Platinum (as Pt) | 7440-06-4 | - | - | - |"
    },
    {
      "substance": "Platinum, metal",
      "pel_mgm3": "1",
      "id": "platinum-metal",
      "url": "https://referencesource.org/workplace-exposure-limits/platinum-metal/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440064 | | Platinum, metal | -- | 1"
    },
    {
      "substance": "Portland cement",
      "cas_number": "65997-15-1",
      "id": "portland-cement",
      "url": "https://referencesource.org/workplace-exposure-limits/portland-cement/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Portland cement | 65997-15-1 | - | - | - |"
    },
    {
      "substance": "Potassium hydroxide; caustic potash",
      "pel_mgm3": "2",
      "ceiling": "C",
      "id": "potassium-hydroxide-caustic-potash",
      "url": "https://referencesource.org/workplace-exposure-limits/potassium-hydroxide-caustic-potash/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1310583 | | Potassium hydroxide; caustic potash | -- | 2 | C"
    },
    {
      "substance": "Potassium stearate",
      "pel_mgm3": "10",
      "id": "potassium-stearate",
      "url": "https://referencesource.org/workplace-exposure-limits/potassium-stearate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "593293 | | Potassium stearate | -- | 10"
    },
    {
      "substance": "Propane",
      "cas_number": "74-98-6",
      "pel_ppm": "1000",
      "pel_mgm3": "1800",
      "id": "propane",
      "url": "https://referencesource.org/workplace-exposure-limits/propane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Propane | 74-98-6 | 1000 | 1800 | - |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "1800",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Propane | 74-98-6 | 1000 | 1800 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1800 (h)",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "74986 | | Propane | 1000 | 1800 (h)",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Propargyl alcohol; 2-propyn-1-o1",
      "pel_ppm": "1",
      "pel_mgm3": "2",
      "id": "propargyl-alcohol-2-propyn-1-o1",
      "url": "https://referencesource.org/workplace-exposure-limits/propargyl-alcohol-2-propyn-1-o1/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107197 | S | Propargyl alcohol; 2-propyn-1-o1 | 1 | 2"
    },
    {
      "substance": "Propionic acid",
      "pel_ppm": "10",
      "pel_mgm3": "30",
      "id": "propionic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/propionic-acid/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "79094 | | Propionic acid | 10 | 30"
    },
    {
      "substance": "Propoxur; 2-isopropoxyphenyl N-methyl carbamate",
      "pel_mgm3": "0.5",
      "id": "propoxur-2-isopropoxyphenyl-n-methyl-carbamate",
      "url": "https://referencesource.org/workplace-exposure-limits/propoxur-2-isopropoxyphenyl-n-methyl-carbamate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "114261 | | Propoxur; 2-isopropoxyphenyl N-methyl carbamate | | 0.5"
    },
    {
      "substance": "Propylene",
      "id": "propylene",
      "url": "https://referencesource.org/workplace-exposure-limits/propylene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "115071 | | Propylene | (h) | --"
    },
    {
      "substance": "Propylene dichloride",
      "cas_number": "78-87-5",
      "pel_ppm": "75",
      "pel_mgm3": "350",
      "id": "propylene-dichloride",
      "url": "https://referencesource.org/workplace-exposure-limits/propylene-dichloride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Propylene dichloride | 78-87-5 | 75 | 350 | - |"
    },
    {
      "substance": "Propylene dichloride; 1,2-dichloropropane",
      "pel_ppm": "75",
      "pel_mgm3": "350",
      "stel_ppm": "110",
      "stel_mgm3": "510",
      "id": "propylene-dichloride-1-2-dichloropropane",
      "url": "https://referencesource.org/workplace-exposure-limits/propylene-dichloride-1-2-dichloropropane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78875 | | Propylene dichloride; 1,2-dichloropropane | 75 | 350 | | 110 | 510"
    },
    {
      "substance": "Propylene glycol dinitrate; PGDN",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.3",
      "id": "propylene-glycol-dinitrate-pgdn",
      "url": "https://referencesource.org/workplace-exposure-limits/propylene-glycol-dinitrate-pgdn/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "6423434 | S | Propylene glycol dinitrate; PGDN | 0.05 | 0.3"
    },
    {
      "substance": "Propylene glycol monomethyl ether",
      "pel_ppm": "100",
      "pel_mgm3": "360",
      "stel_ppm": "150",
      "stel_mgm3": "540",
      "id": "propylene-glycol-monomethyl-ether",
      "url": "https://referencesource.org/workplace-exposure-limits/propylene-glycol-monomethyl-ether/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107982 | S | Propylene glycol monomethyl ether | 100 | 360 | | 150 | 540"
    },
    {
      "substance": "Propylene glycol monomethyl ether acetate",
      "pel_ppm": "100",
      "pel_mgm3": "541",
      "stel_ppm": "150",
      "stel_mgm3": "811",
      "id": "propylene-glycol-monomethyl-ether-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/propylene-glycol-monomethyl-ether-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108656 | S | Propylene glycol monomethyl ether acetate | 100 | 541 | | 150 | 811"
    },
    {
      "substance": "Propylene imine",
      "cas_number": "75-55-8",
      "pel_ppm": "2",
      "pel_mgm3": "5",
      "id": "propylene-imine",
      "url": "https://referencesource.org/workplace-exposure-limits/propylene-imine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Propylene imine | 75-55-8 | 2 | 5 | X |"
    },
    {
      "substance": "Propylene oxide",
      "cas_number": "75-56-9",
      "pel_ppm": "100",
      "pel_mgm3": "240",
      "id": "propylene-oxide",
      "url": "https://referencesource.org/workplace-exposure-limits/propylene-oxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Propylene oxide | 75-56-9 | 100 | 240 | - |"
    },
    {
      "substance": "Propylene oxide; 1,2-epoxy-propane",
      "pel_ppm": "2",
      "pel_mgm3": "4.75",
      "id": "propylene-oxide-1-2-epoxy-propane",
      "url": "https://referencesource.org/workplace-exposure-limits/propylene-oxide-1-2-epoxy-propane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75569 | | Propylene oxide; 1,2-epoxy-propane | 2 | 4.75"
    },
    {
      "substance": "Propyleneimine; 2-methylaziridine",
      "pel_ppm": "2",
      "pel_mgm3": "5",
      "id": "propyleneimine-2-methylaziridine",
      "url": "https://referencesource.org/workplace-exposure-limits/propyleneimine-2-methylaziridine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75558 | S | Propyleneimine; 2-methylaziridine | 2 | 5"
    },
    {
      "substance": "Propyne; see Methylacetylene",
      "id": "propyne-see-methylacetylene",
      "url": "https://referencesource.org/workplace-exposure-limits/propyne-see-methylacetylene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74997 | | Propyne; see Methylacetylene"
    },
    {
      "substance": "Pyrethrum",
      "cas_number": "8003-34-7",
      "pel_mgm3": "5",
      "id": "pyrethrum",
      "url": "https://referencesource.org/workplace-exposure-limits/pyrethrum/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Pyrethrum | 8003-34-7 | - | 5 | - |",
      "disagreements": []
    },
    {
      "substance": "Pyridine",
      "cas_number": "110-86-1",
      "pel_ppm": "5",
      "pel_mgm3": "15",
      "id": "pyridine",
      "url": "https://referencesource.org/workplace-exposure-limits/pyridine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Pyridine | 110-86-1 | 5 | 15 | - |",
      "disagreements": []
    },
    {
      "substance": "Quartz,",
      "pel_mgm3": "0.05",
      "id": "quartz",
      "url": "https://referencesource.org/workplace-exposure-limits/quartz/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "14808607 | | Quartz, | -- | 0.05"
    },
    {
      "substance": "Quartz; see 1910.1053 7",
      "cas_number": "14808-60-7",
      "id": "quartz-see-1910-1053-7",
      "url": "https://referencesource.org/workplace-exposure-limits/quartz-see-1910-1053-7/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Quartz; see 1910.1053 7 | 14808-60-7 | - | - | - |"
    },
    {
      "substance": "Quinone",
      "cas_number": "106-51-4",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.4",
      "id": "quinone",
      "url": "https://referencesource.org/workplace-exposure-limits/quinone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Quinone | 106-51-4 | 0.1 | 0.4 | - |",
      "disagreements": []
    },
    {
      "substance": "RDX; see Cyclonite",
      "id": "rdx-see-cyclonite",
      "url": "https://referencesource.org/workplace-exposure-limits/rdx-see-cyclonite/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "121824 | | RDX; see Cyclonite"
    },
    {
      "substance": "Resorcinol",
      "pel_ppm": "10",
      "pel_mgm3": "45",
      "stel_ppm": "20",
      "stel_mgm3": "90",
      "id": "resorcinol",
      "url": "https://referencesource.org/workplace-exposure-limits/resorcinol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108463 | | Resorcinol | 10 | 45 | | 20 | 90"
    },
    {
      "substance": "Rhodium (as Rh), metal fume and insoluble compounds",
      "cas_number": "7440-16-6",
      "pel_mgm3": "0.1",
      "id": "rhodium-as-rh-metal-fume-and-insoluble-compounds",
      "url": "https://referencesource.org/workplace-exposure-limits/rhodium-as-rh-metal-fume-and-insoluble-compounds/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Rhodium (as Rh), metal fume and insoluble compounds | 7440-16-6 | - | 0.1 | - |"
    },
    {
      "substance": "Rhodium (as Rh), soluble compounds",
      "cas_number": "7440-16-6",
      "pel_mgm3": "0.001",
      "id": "rhodium-as-rh-soluble-compounds",
      "url": "https://referencesource.org/workplace-exposure-limits/rhodium-as-rh-soluble-compounds/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Rhodium (as Rh), soluble compounds | 7440-16-6 | - | 0.001 | - |"
    },
    {
      "substance": "Rhodium, metal",
      "pel_mgm3": "0.1",
      "id": "rhodium-metal",
      "url": "https://referencesource.org/workplace-exposure-limits/rhodium-metal/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440166 | | Rhodium, metal | -- | 0.1"
    },
    {
      "substance": "Ronnel",
      "cas_number": "299-84-3",
      "pel_mgm3": "15",
      "id": "ronnel",
      "url": "https://referencesource.org/workplace-exposure-limits/ronnel/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Ronnel | 299-84-3 | - | 15 | - |"
    },
    {
      "substance": "Ronnel; o,o-dimethyl o-(2,4,5-trichlorophenyl) phosphorothioite",
      "pel_mgm3": "10",
      "id": "ronnel-o-o-dimethyl-o-2-4-5-trichlorophenyl-phosphorothioite",
      "url": "https://referencesource.org/workplace-exposure-limits/ronnel-o-o-dimethyl-o-2-4-5-trichlorophenyl-phosphorothioite/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "299843 | | Ronnel; o,o-dimethyl o-(2,4,5-trichlorophenyl) phosphorothioite | -- | 10"
    },
    {
      "substance": "Rotenone",
      "cas_number": "83-79-4",
      "pel_mgm3": "5",
      "id": "rotenone",
      "url": "https://referencesource.org/workplace-exposure-limits/rotenone/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Rotenone | 83-79-4 | - | 5 | - |"
    },
    {
      "substance": "Rotenone, commercial",
      "pel_mgm3": "5",
      "id": "rotenone-commercial",
      "url": "https://referencesource.org/workplace-exposure-limits/rotenone-commercial/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "83794 | | Rotenone, commercial | -- | 5"
    },
    {
      "substance": "Rouge; see Particulates not otherwise regulated",
      "id": "rouge-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/rouge-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1309371 | | Rouge; see Particulates not otherwise regulated"
    },
    {
      "substance": "sec-Amyl acetate",
      "cas_number": "626-38-0",
      "pel_ppm": "125",
      "pel_mgm3": "650",
      "id": "sec-amyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/sec-amyl-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "sec-Amyl acetate | 626-38-0 | 125 | 650 | - |"
    },
    {
      "substance": "sec-Amyl acetate (all isomers and mixtures); see Pentyl acetate",
      "id": "sec-amyl-acetate-all-isomers-and-mixtures-see-pentyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/sec-amyl-acetate-all-isomers-and-mixtures-see-pentyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "626380 | | sec-Amyl acetate (all isomers and mixtures); see Pentyl acetate"
    },
    {
      "substance": "sec-Butyl acetate",
      "cas_number": "105-46-4",
      "pel_ppm": "200",
      "pel_mgm3": "950",
      "id": "sec-butyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/sec-butyl-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "sec-Butyl acetate | 105-46-4 | 200 | 950 | - |",
      "disagreements": []
    },
    {
      "substance": "sec-Butyl alcohol",
      "cas_number": "78-92-2",
      "pel_ppm": "150",
      "pel_mgm3": "450",
      "id": "sec-butyl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/sec-butyl-alcohol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "sec-Butyl alcohol | 78-92-2 | 150 | 450 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "150",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "sec-Butyl alcohol | 78-92-2 | 150 | 450 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "100",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "78922 | | sec-Butyl alcohol | 100 | 305",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "450",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "sec-Butyl alcohol | 78-92-2 | 150 | 450 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "305",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "78922 | | sec-Butyl alcohol | 100 | 305",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "sec-Hexyl acetate",
      "cas_number": "108-84-9",
      "pel_ppm": "50",
      "pel_mgm3": "300",
      "id": "sec-hexyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/sec-hexyl-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "sec-Hexyl acetate | 108-84-9 | 50 | 300 | - |"
    },
    {
      "substance": "sec-Hexyl acetate; 4-methyl-2-pentyl acetate; 1,3-dimethyl-butyl acetate",
      "pel_ppm": "50",
      "pel_mgm3": "300",
      "id": "sec-hexyl-acetate-4-methyl-2-pentyl-acetate-1-3-dimethyl-butyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/sec-hexyl-acetate-4-methyl-2-pentyl-acetate-1-3-dimethyl-butyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108849 | | sec-Hexyl acetate; 4-methyl-2-pentyl acetate; 1,3-dimethyl-butyl acetate | 50 | 300"
    },
    {
      "substance": "Selenium compounds (as Se)",
      "cas_number": "7782-49-2",
      "pel_mgm3": "0.2",
      "id": "selenium-compounds-as-se",
      "url": "https://referencesource.org/workplace-exposure-limits/selenium-compounds-as-se/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Selenium compounds (as Se) | 7782-49-2 | - | 0.2 | - |"
    },
    {
      "substance": "Selenium hexafluoride",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.4",
      "id": "selenium-hexafluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/selenium-hexafluoride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7783791 | | Selenium hexafluoride | 0.05 | 0.4"
    },
    {
      "substance": "Selenium hexafluoride (as Se)",
      "cas_number": "7783-79-1",
      "pel_ppm": "0.05",
      "pel_mgm3": "0.4",
      "id": "selenium-hexafluoride-as-se",
      "url": "https://referencesource.org/workplace-exposure-limits/selenium-hexafluoride-as-se/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Selenium hexafluoride (as Se) | 7783-79-1 | 0.05 | 0.4 | - |"
    },
    {
      "substance": "Sesone; sodium 2,4-dichloro-phenoxyethyl sulfate",
      "id": "sesone-sodium-2-4-dichloro-phenoxyethyl-sulfate",
      "url": "https://referencesource.org/workplace-exposure-limits/sesone-sodium-2-4-dichloro-phenoxyethyl-sulfate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "136787 | | Sesone; sodium 2,4-dichloro-phenoxyethyl sulfate"
    },
    {
      "substance": "Silica, amorphous Diatomaceous earth",
      "id": "silica-amorphous-diatomaceous-earth",
      "url": "https://referencesource.org/workplace-exposure-limits/silica-amorphous-diatomaceous-earth/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "61790532 | | Silica, amorphous Diatomaceous earth"
    },
    {
      "substance": "Silica, amorphous, diatomaceous earth, containing less than 1% crystalline silica",
      "cas_number": "61790-53-2",
      "id": "silica-amorphous-diatomaceous-earth-containing-less-than-1-crystalline-silica",
      "url": "https://referencesource.org/workplace-exposure-limits/silica-amorphous-diatomaceous-earth-containing-less-than-1-crystalline-silica/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Silica, amorphous, diatomaceous earth, containing less than 1% crystalline silica | 61790-53-2 | - | ( 3 ) | - |"
    },
    {
      "substance": "Silica, amorphous, precipitated and gel",
      "cas_number": "112926-00-8",
      "id": "silica-amorphous-precipitated-and-gel",
      "url": "https://referencesource.org/workplace-exposure-limits/silica-amorphous-precipitated-and-gel/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Silica, amorphous, precipitated and gel | 112926-00-8 | - | ( 3 ) | - |"
    },
    {
      "substance": "Silica, fused, respirable dust",
      "cas_number": "60676-86-0",
      "id": "silica-fused-respirable-dust",
      "url": "https://referencesource.org/workplace-exposure-limits/silica-fused-respirable-dust/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Silica, fused, respirable dust | 60676-86-0 | - | ( 3 ) | - |",
      "disagreements": []
    },
    {
      "substance": "Silicon",
      "cas_number": "7440-21-3",
      "id": "silicon",
      "url": "https://referencesource.org/workplace-exposure-limits/silicon/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Silicon | 7440-21-3 | - | - | - |"
    },
    {
      "substance": "Silicon carbide",
      "cas_number": "409-21-2",
      "id": "silicon-carbide",
      "url": "https://referencesource.org/workplace-exposure-limits/silicon-carbide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Silicon carbide | 409-21-2 | - | - | - |"
    },
    {
      "substance": "Silicon carbide; SiC; see Particulates not otherwise regulated",
      "id": "silicon-carbide-sic-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/silicon-carbide-sic-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "409212 | | Silicon carbide; SiC; see Particulates not otherwise regulated"
    },
    {
      "substance": "Silicon; see Particulates not otherwise regulated",
      "id": "silicon-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/silicon-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440213 | | Silicon; see Particulates not otherwise regulated"
    },
    {
      "substance": "Silicon tetrahydride; silane",
      "pel_ppm": "5",
      "pel_mgm3": "7",
      "id": "silicon-tetrahydride-silane",
      "url": "https://referencesource.org/workplace-exposure-limits/silicon-tetrahydride-silane/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7803625 | | Silicon tetrahydride; silane | 5 | 7"
    },
    {
      "substance": "Silver, metal and soluble compounds (as Ag)",
      "cas_number": "7440-22-4",
      "pel_mgm3": "0.01",
      "id": "silver-metal-and-soluble-compounds-as-ag",
      "url": "https://referencesource.org/workplace-exposure-limits/silver-metal-and-soluble-compounds-as-ag/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Silver, metal and soluble compounds (as Ag) | 7440-22-4 | - | 0.01 | - |"
    },
    {
      "substance": "Silver metal, as Ag",
      "pel_mgm3": "0.01",
      "id": "silver-metal-as-ag",
      "url": "https://referencesource.org/workplace-exposure-limits/silver-metal-as-ag/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440224 | | Silver metal, as Ag | -- | 0.01"
    },
    {
      "substance": "Sodium 2,4-dichlorophenoxyethyl sulfate; see Sesone",
      "id": "sodium-2-4-dichlorophenoxyethyl-sulfate-see-sesone",
      "url": "https://referencesource.org/workplace-exposure-limits/sodium-2-4-dichlorophenoxyethyl-sulfate-see-sesone/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "136787 | | Sodium 2,4-dichlorophenoxyethyl sulfate; see Sesone"
    },
    {
      "substance": "Sodium azide",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.3",
      "ceiling": "C",
      "id": "sodium-azide",
      "url": "https://referencesource.org/workplace-exposure-limits/sodium-azide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "26628228 | S | Sodium azide | 0.1 | 0.3 | C"
    },
    {
      "substance": "Sodium bisulfite",
      "pel_mgm3": "5",
      "id": "sodium-bisulfite",
      "url": "https://referencesource.org/workplace-exposure-limits/sodium-bisulfite/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7631905 | | Sodium bisulfite | -- | 5"
    },
    {
      "substance": "Sodium fluoroacetate",
      "cas_number": "62-74-8",
      "pel_mgm3": "0.05",
      "id": "sodium-fluoroacetate",
      "url": "https://referencesource.org/workplace-exposure-limits/sodium-fluoroacetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Sodium fluoroacetate | 62-74-8 | - | 0.05 | X |",
      "disagreements": []
    },
    {
      "substance": "Sodium hydroxide",
      "cas_number": "1310-73-2",
      "pel_mgm3": "2",
      "id": "sodium-hydroxide",
      "url": "https://referencesource.org/workplace-exposure-limits/sodium-hydroxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Sodium hydroxide | 1310-73-2 | - | 2 | - |"
    },
    {
      "substance": "Sodium hydroxide; caustic soda",
      "pel_mgm3": "2",
      "ceiling": "C",
      "id": "sodium-hydroxide-caustic-soda",
      "url": "https://referencesource.org/workplace-exposure-limits/sodium-hydroxide-caustic-soda/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1310732 | | Sodium hydroxide; caustic soda | -- | 2 | C"
    },
    {
      "substance": "Sodium metabisulfite",
      "pel_mgm3": "5",
      "id": "sodium-metabisulfite",
      "url": "https://referencesource.org/workplace-exposure-limits/sodium-metabisulfite/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7681574 | | Sodium metabisulfite | -- | 5"
    },
    {
      "substance": "Sodium stearate",
      "pel_mgm3": "10",
      "id": "sodium-stearate",
      "url": "https://referencesource.org/workplace-exposure-limits/sodium-stearate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "822162 | | Sodium stearate | -- | 10"
    },
    {
      "substance": "Starch",
      "cas_number": "9005-25-8",
      "id": "starch",
      "url": "https://referencesource.org/workplace-exposure-limits/starch/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Starch | 9005-25-8 | - | - | - |"
    },
    {
      "substance": "Starch; see Particulates not otherwise regulated",
      "id": "starch-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/starch-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "9005258 | | Starch; see Particulates not otherwise regulated"
    },
    {
      "substance": "Stibine",
      "cas_number": "7803-52-3",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.5",
      "id": "stibine",
      "url": "https://referencesource.org/workplace-exposure-limits/stibine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Stibine | 7803-52-3 | 0.1 | 0.5 | - |"
    },
    {
      "substance": "Stibine; SbH $3",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.5",
      "id": "stibine-sbh-3",
      "url": "https://referencesource.org/workplace-exposure-limits/stibine-sbh-3/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7803523 | | Stibine; SbH $3 | 0.1 | 0.5"
    },
    {
      "substance": "Stoddard solvent",
      "cas_number": "8052-41-3",
      "pel_ppm": "500",
      "pel_mgm3": "2900",
      "id": "stoddard-solvent",
      "url": "https://referencesource.org/workplace-exposure-limits/stoddard-solvent/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Stoddard solvent | 8052-41-3 | 500 | 2900 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "500",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Stoddard solvent | 8052-41-3 | 500 | 2900 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "100",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "8052413 | | Stoddard solvent | 100 | 525",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "2900",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Stoddard solvent | 8052-41-3 | 500 | 2900 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "525",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "8052413 | | Stoddard solvent | 100 | 525",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Strontium chromate, as Cr (see also Sections 1532.2, 5206 & 8359) Stearates; see specific compound",
      "pel_mgm3": "0.0005",
      "id": "strontium-chromate-as-cr-see-also-sections-1532-2-5206-8359-stearates-see-specif",
      "url": "https://referencesource.org/workplace-exposure-limits/strontium-chromate-as-cr-see-also-sections-1532-2-5206-8359-stearates-see-specif/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7789062 | | Strontium chromate, as Cr (see also Sections 1532.2, 5206 & 8359) Stearates; see specific compound | -- | 0.0005"
    },
    {
      "substance": "Strychnine",
      "cas_number": "57-24-9",
      "pel_mgm3": "0.15",
      "id": "strychnine",
      "url": "https://referencesource.org/workplace-exposure-limits/strychnine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Strychnine | 57-24-9 | - | 0.15 | - |",
      "disagreements": []
    },
    {
      "substance": "Styrene",
      "cas_number": "100-42-5",
      "id": "styrene",
      "url": "https://referencesource.org/workplace-exposure-limits/styrene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Styrene | 100-42-5 | - | ( 2 ) | - |"
    },
    {
      "substance": "Styrene (monomer); phenylethylene",
      "pel_ppm": "50",
      "pel_mgm3": "215",
      "ceiling": "500 ppm",
      "stel_ppm": "100",
      "stel_mgm3": "425",
      "id": "styrene-monomer-phenylethylene",
      "url": "https://referencesource.org/workplace-exposure-limits/styrene-monomer-phenylethylene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "100425 | S | Styrene (monomer); phenylethylene | 50 | 215 | 500 ppm | 100 | 425"
    },
    {
      "substance": "Subtilisins (as pure crystalline proteolytic enzymes)",
      "stel_mgm3": "0.00006 (r)",
      "id": "subtilisins-as-pure-crystalline-proteolytic-enzymes",
      "url": "https://referencesource.org/workplace-exposure-limits/subtilisins-as-pure-crystalline-proteolytic-enzymes/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "9014011 | | Subtilisins (as pure crystalline proteolytic enzymes) | -- | | | | 0.00006 (r)"
    },
    {
      "substance": "Sucrose",
      "cas_number": "57-50-1",
      "id": "sucrose",
      "url": "https://referencesource.org/workplace-exposure-limits/sucrose/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Sucrose | 57-50-1 | - | - | - |"
    },
    {
      "substance": "Sucrose; see Particulates not otherwise regulated",
      "id": "sucrose-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/sucrose-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "57501 | | Sucrose; see Particulates not otherwise regulated"
    },
    {
      "substance": "Sulfometuron methyl",
      "pel_mgm3": "3.5",
      "id": "sulfometuron-methyl",
      "url": "https://referencesource.org/workplace-exposure-limits/sulfometuron-methyl/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "74222972 | | Sulfometuron methyl | -- | 3.5"
    },
    {
      "substance": "Sulfotep; tetraethyl dithionopyrophosphate",
      "pel_mgm3": "0.2",
      "id": "sulfotep-tetraethyl-dithionopyrophosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/sulfotep-tetraethyl-dithionopyrophosphate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "3689245 | S | Sulfotep; tetraethyl dithionopyrophosphate | | 0.2"
    },
    {
      "substance": "Sulfur dioxide",
      "cas_number": "7446-09-5",
      "pel_ppm": "5",
      "pel_mgm3": "13",
      "id": "sulfur-dioxide",
      "url": "https://referencesource.org/workplace-exposure-limits/sulfur-dioxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Sulfur dioxide | 7446-09-5 | 5 | 13 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "5",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Sulfur dioxide | 7446-09-5 | 5 | 13 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "2",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7446095 | | Sulfur dioxide | 2 | 5 | | 5 | 10",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "13",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Sulfur dioxide | 7446-09-5 | 5 | 13 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7446095 | | Sulfur dioxide | 2 | 5 | | 5 | 10",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Sulfur hexafluoride",
      "cas_number": "2551-62-4",
      "pel_ppm": "1000",
      "pel_mgm3": "6000",
      "id": "sulfur-hexafluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/sulfur-hexafluoride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Sulfur hexafluoride | 2551-62-4 | 1000 | 6000 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "1000",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Sulfur hexafluoride | 2551-62-4 | 1000 | 6000 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1,000",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "2551624 | | Sulfur hexafluoride | 1,000 | 6,000",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "6000",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Sulfur hexafluoride | 2551-62-4 | 1000 | 6000 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "6,000",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "2551624 | | Sulfur hexafluoride | 1,000 | 6,000",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Sulfur monochloride",
      "cas_number": "10025-67-9",
      "pel_ppm": "1",
      "pel_mgm3": "6",
      "id": "sulfur-monochloride",
      "url": "https://referencesource.org/workplace-exposure-limits/sulfur-monochloride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Sulfur monochloride | 10025-67-9 | 1 | 6 | - |"
    },
    {
      "substance": "Sulfur monochloride; S $2 Cl $2",
      "pel_ppm": "1",
      "pel_mgm3": "6",
      "ceiling": "C",
      "id": "sulfur-monochloride-s-2-cl-2",
      "url": "https://referencesource.org/workplace-exposure-limits/sulfur-monochloride-s-2-cl-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "10025679 | | Sulfur monochloride; S $2 Cl $2 | 1 | 6 | C"
    },
    {
      "substance": "Sulfur pentafluoride",
      "cas_number": "5714-22-7",
      "pel_ppm": "0.025",
      "pel_mgm3": "0.25",
      "id": "sulfur-pentafluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/sulfur-pentafluoride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Sulfur pentafluoride | 5714-22-7 | 0.025 | 0.25 | - |"
    },
    {
      "substance": "Sulfur pentafluoride; S $2 F $10",
      "pel_ppm": "0.01",
      "pel_mgm3": "0.1",
      "ceiling": "C",
      "id": "sulfur-pentafluoride-s-2-f-10",
      "url": "https://referencesource.org/workplace-exposure-limits/sulfur-pentafluoride-s-2-f-10/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "5714227 | | Sulfur pentafluoride; S $2 F $10 | 0.01 | 0.1 | C"
    },
    {
      "substance": "Sulfur tetrafluoride",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.4",
      "ceiling": "C",
      "id": "sulfur-tetrafluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/sulfur-tetrafluoride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7783600 | | Sulfur tetrafluoride | 0.1 | 0.4 | C"
    },
    {
      "substance": "Sulfuric acid",
      "cas_number": "7664-93-9",
      "pel_mgm3": "1",
      "id": "sulfuric-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/sulfuric-acid/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Sulfuric acid | 7664-93-9 | - | 1 | - |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "1",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Sulfuric acid | 7664-93-9 | - | 1 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "7664939 | | Sulfuric acid | -- | 0.1 | | -- | 3",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Sulfuryl fluoride",
      "cas_number": "2699-79-8",
      "pel_ppm": "5",
      "pel_mgm3": "20",
      "id": "sulfuryl-fluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/sulfuryl-fluoride/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Sulfuryl fluoride | 2699-79-8 | 5 | 20 | - |"
    },
    {
      "substance": "Sulfuryl fluoride; SO $2 F $2",
      "pel_ppm": "5",
      "pel_mgm3": "20",
      "stel_ppm": "10",
      "stel_mgm3": "40",
      "id": "sulfuryl-fluoride-so-2-f-2",
      "url": "https://referencesource.org/workplace-exposure-limits/sulfuryl-fluoride-so-2-f-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "2699798 | | Sulfuryl fluoride; SO $2 F $2 | 5 | 20 | | 10 | 40"
    },
    {
      "substance": "Sulprofos",
      "pel_mgm3": "1",
      "id": "sulprofos",
      "url": "https://referencesource.org/workplace-exposure-limits/sulprofos/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "35400432 | | Sulprofos | | 1"
    },
    {
      "substance": "Talc (containing no asbestos fibers), respirable dust",
      "pel_mgm3": "2",
      "id": "talc-containing-no-asbestos-fibers-respirable-dust",
      "url": "https://referencesource.org/workplace-exposure-limits/talc-containing-no-asbestos-fibers-respirable-dust/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "14807966 | | Talc (containing no asbestos fibers), respirable dust | -- | 2"
    },
    {
      "substance": "Talc (containing no asbestos), respirable dust",
      "cas_number": "14807-96-6",
      "id": "talc-containing-no-asbestos-respirable-dust",
      "url": "https://referencesource.org/workplace-exposure-limits/talc-containing-no-asbestos-respirable-dust/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Talc (containing no asbestos), respirable dust | 14807-96-6 | - | ( 3 ) | - |"
    },
    {
      "substance": "Tantalum, metal and oxide dust",
      "cas_number": "7440-25-7",
      "pel_mgm3": "5",
      "id": "tantalum-metal-and-oxide-dust",
      "url": "https://referencesource.org/workplace-exposure-limits/tantalum-metal-and-oxide-dust/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tantalum, metal and oxide dust | 7440-25-7 | - | 5 | - |"
    },
    {
      "substance": "Tantalum metal dust, as Ta",
      "pel_mgm3": "5",
      "id": "tantalum-metal-dust-as-ta",
      "url": "https://referencesource.org/workplace-exposure-limits/tantalum-metal-dust-as-ta/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440257 | | Tantalum metal dust, as Ta | -- | 5"
    },
    {
      "substance": "Tantalum oxide dust, as Ta",
      "pel_mgm3": "5",
      "id": "tantalum-oxide-dust-as-ta",
      "url": "https://referencesource.org/workplace-exposure-limits/tantalum-oxide-dust-as-ta/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1314610 | | Tantalum oxide dust, as Ta | -- | 5"
    },
    {
      "substance": "TCP; see Triorthocresyl phosphate",
      "id": "tcp-see-triorthocresyl-phosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/tcp-see-triorthocresyl-phosphate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78308 | | TCP; see Triorthocresyl phosphate"
    },
    {
      "substance": "TDI; see Toluene-2,4-diisocyanate",
      "id": "tdi-see-toluene-2-4-diisocyanate",
      "url": "https://referencesource.org/workplace-exposure-limits/tdi-see-toluene-2-4-diisocyanate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "584849 | | TDI; see Toluene-2,4-diisocyanate"
    },
    {
      "substance": "TEDP; see Sulfotep",
      "id": "tedp-see-sulfotep",
      "url": "https://referencesource.org/workplace-exposure-limits/tedp-see-sulfotep/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "3689245 | S | TEDP; see Sulfotep"
    },
    {
      "substance": "TEDP (Sulfotep)",
      "cas_number": "3689-24-5",
      "pel_mgm3": "0.2",
      "id": "tedp-sulfotep",
      "url": "https://referencesource.org/workplace-exposure-limits/tedp-sulfotep/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "TEDP (Sulfotep) | 3689-24-5 | - | 0.2 | X |"
    },
    {
      "substance": "Tellurium and compounds (as Te)",
      "cas_number": "13494-80-9",
      "pel_mgm3": "0.1",
      "id": "tellurium-and-compounds-as-te",
      "url": "https://referencesource.org/workplace-exposure-limits/tellurium-and-compounds-as-te/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tellurium and compounds (as Te) | 13494-80-9 | - | 0.1 | - |"
    },
    {
      "substance": "Tellurium hexafluoride",
      "pel_ppm": "0.02",
      "pel_mgm3": "0.2",
      "id": "tellurium-hexafluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/tellurium-hexafluoride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7783804 | | Tellurium hexafluoride | 0.02 | 0.2"
    },
    {
      "substance": "Tellurium hexafluoride (as Te)",
      "cas_number": "7783-80-4",
      "pel_ppm": "0.02",
      "pel_mgm3": "0.2",
      "id": "tellurium-hexafluoride-as-te",
      "url": "https://referencesource.org/workplace-exposure-limits/tellurium-hexafluoride-as-te/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tellurium hexafluoride (as Te) | 7783-80-4 | 0.02 | 0.2 | - |"
    },
    {
      "substance": "Temephos",
      "cas_number": "3383-96-8",
      "id": "temephos",
      "url": "https://referencesource.org/workplace-exposure-limits/temephos/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Temephos | 3383-96-8 | - | - | - |"
    },
    {
      "substance": "Temephos; o,o,o\u2032 ,o\u2032-tetramethyl o,o\u2032-thiodi-p-phenylene phosphorothioate Total dust",
      "pel_mgm3": "10",
      "id": "temephos-o-o-o-o-tetramethyl-o-o-thiodi-p-phenylene-phosphorothioate-total-dust",
      "url": "https://referencesource.org/workplace-exposure-limits/temephos-o-o-o-o-tetramethyl-o-o-thiodi-p-phenylene-phosphorothioate-total-dust/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "3383968 | | Temephos; o,o,o\u2032 ,o\u2032-tetramethyl o,o\u2032-thiodi-p-phenylene phosphorothioate Total dust | -- | 10"
    },
    {
      "substance": "TEPP (Tetraethyl pyrophosphate)",
      "cas_number": "107-49-3",
      "pel_mgm3": "0.05",
      "id": "tepp-tetraethyl-pyrophosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/tepp-tetraethyl-pyrophosphate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "TEPP (Tetraethyl pyrophosphate) | 107-49-3 | - | 0.05 | X |"
    },
    {
      "substance": "TEPP; tetraethyl pyrophosphate;",
      "pel_ppm": "0.004",
      "pel_mgm3": "0.05",
      "id": "tepp-tetraethyl-pyrophosphate-2",
      "url": "https://referencesource.org/workplace-exposure-limits/tepp-tetraethyl-pyrophosphate-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107493 | S | TEPP; tetraethyl pyrophosphate; | 0.004 | 0.05"
    },
    {
      "substance": "Terephthalic acid",
      "pel_mgm3": "10",
      "id": "terephthalic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/terephthalic-acid/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "100210 | | Terephthalic acid | -- | 10"
    },
    {
      "substance": "Terphenyls",
      "cas_number": "26140-60-3",
      "pel_ppm": "(C)1",
      "pel_mgm3": "(C)9",
      "id": "terphenyls",
      "url": "https://referencesource.org/workplace-exposure-limits/terphenyls/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Terphenyls | 26140-60-3 | (C)1 | (C)9 | - |"
    },
    {
      "substance": "tert-Amyl acetate; see Pentyl acetate",
      "id": "tert-amyl-acetate-see-pentyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/tert-amyl-acetate-see-pentyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "625161 | | tert-Amyl acetate; see Pentyl acetate"
    },
    {
      "substance": "tert-Butyl acetate",
      "cas_number": "540-88-5",
      "pel_ppm": "200",
      "pel_mgm3": "950",
      "id": "tert-butyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/tert-butyl-acetate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "tert-Butyl acetate | 540-88-5 | 200 | 950 | - |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "950",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "tert-Butyl acetate | 540-88-5 | 200 | 950 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "955",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "540885 | | tert-Butyl acetate | 200 | 955",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "tert-Butyl alcohol",
      "cas_number": "75-65-0",
      "pel_ppm": "100",
      "pel_mgm3": "300",
      "id": "tert-butyl-alcohol",
      "url": "https://referencesource.org/workplace-exposure-limits/tert-butyl-alcohol/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "tert-Butyl alcohol | 75-65-0 | 100 | 300 | - |",
      "disagreements": []
    },
    {
      "substance": "tert-Butyl chromate (as CrO 3 ); see 1910.1026 6",
      "cas_number": "1189-85-1",
      "id": "tert-butyl-chromate-as-cro-3-see-1910-1026-6",
      "url": "https://referencesource.org/workplace-exposure-limits/tert-butyl-chromate-as-cro-3-see-1910-1026-6/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "tert-Butyl chromate (as CrO 3 ); see 1910.1026 6 | 1189-85-1 | - | - | - |"
    },
    {
      "substance": "tert-Butyl chromate; di-tert-butyl Chromate, as CrO $3",
      "pel_mgm3": "0.1",
      "ceiling": "C",
      "id": "tert-butyl-chromate-di-tert-butyl-chromate-as-cro-3",
      "url": "https://referencesource.org/workplace-exposure-limits/tert-butyl-chromate-di-tert-butyl-chromate-as-cro-3/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1189851 | S | tert-Butyl chromate; di-tert-butyl Chromate, as CrO $3 | -- | 0.1 | C"
    },
    {
      "substance": "Tetrachloroethylene; see Perchloroethylene",
      "id": "tetrachloroethylene-see-perchloroethylene",
      "url": "https://referencesource.org/workplace-exposure-limits/tetrachloroethylene-see-perchloroethylene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "127184 | | Tetrachloroethylene; see Perchloroethylene"
    },
    {
      "substance": "Tetrachloromethane; see Carbon tetrachloride",
      "id": "tetrachloromethane-see-carbon-tetrachloride",
      "url": "https://referencesource.org/workplace-exposure-limits/tetrachloromethane-see-carbon-tetrachloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "56235 | | Tetrachloromethane; see Carbon tetrachloride"
    },
    {
      "substance": "Tetrachloronaphthalene",
      "cas_number": "1335-88-2",
      "pel_mgm3": "2",
      "id": "tetrachloronaphthalene",
      "url": "https://referencesource.org/workplace-exposure-limits/tetrachloronaphthalene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tetrachloronaphthalene | 1335-88-2 | - | 2 | X |",
      "disagreements": []
    },
    {
      "substance": "Tetraethyl dithionopyrophosphate; see Sulfotep",
      "id": "tetraethyl-dithionopyrophosphate-see-sulfotep",
      "url": "https://referencesource.org/workplace-exposure-limits/tetraethyl-dithionopyrophosphate-see-sulfotep/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "3689245 | | Tetraethyl dithionopyrophosphate; see Sulfotep"
    },
    {
      "substance": "Tetraethyl lead (as Pb)",
      "cas_number": "78-00-2",
      "pel_mgm3": "0.075",
      "id": "tetraethyl-lead-as-pb",
      "url": "https://referencesource.org/workplace-exposure-limits/tetraethyl-lead-as-pb/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tetraethyl lead (as Pb) | 78-00-2 | - | 0.075 | X |"
    },
    {
      "substance": "Tetraethyl lead; tetraethylplumbane, as Pb",
      "pel_mgm3": "0.075",
      "id": "tetraethyl-lead-tetraethylplumbane-as-pb",
      "url": "https://referencesource.org/workplace-exposure-limits/tetraethyl-lead-tetraethylplumbane-as-pb/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78002 | S | Tetraethyl lead; tetraethylplumbane, as Pb | -- | 0.075"
    },
    {
      "substance": "Tetraethyl pyrophosphate; see TEPP",
      "id": "tetraethyl-pyrophosphate-see-tepp",
      "url": "https://referencesource.org/workplace-exposure-limits/tetraethyl-pyrophosphate-see-tepp/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107493 | | Tetraethyl pyrophosphate; see TEPP"
    },
    {
      "substance": "Tetrahydrofuran",
      "cas_number": "109-99-9",
      "pel_ppm": "200",
      "pel_mgm3": "590",
      "id": "tetrahydrofuran",
      "url": "https://referencesource.org/workplace-exposure-limits/tetrahydrofuran/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tetrahydrofuran | 109-99-9 | 200 | 590 | - |",
      "disagreements": []
    },
    {
      "substance": "Tetramethyl lead (as Pb)",
      "cas_number": "75-74-1",
      "pel_mgm3": "0.075",
      "id": "tetramethyl-lead-as-pb",
      "url": "https://referencesource.org/workplace-exposure-limits/tetramethyl-lead-as-pb/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tetramethyl lead (as Pb) | 75-74-1 | - | 0.075 | X |"
    },
    {
      "substance": "Tetramethyl lead; tetramethylplumbane, as Pb",
      "pel_mgm3": "0.075",
      "id": "tetramethyl-lead-tetramethylplumbane-as-pb",
      "url": "https://referencesource.org/workplace-exposure-limits/tetramethyl-lead-tetramethylplumbane-as-pb/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75741 | S | Tetramethyl lead; tetramethylplumbane, as Pb | -- | 0.075"
    },
    {
      "substance": "Tetramethyl succinonitrile",
      "cas_number": "3333-52-6",
      "pel_ppm": "0.5",
      "pel_mgm3": "3",
      "id": "tetramethyl-succinonitrile",
      "url": "https://referencesource.org/workplace-exposure-limits/tetramethyl-succinonitrile/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tetramethyl succinonitrile | 3333-52-6 | 0.5 | 3 | X |"
    },
    {
      "substance": "Tetramethyl succinonitrile (decomposition product of 2,2\u2032-azobisisobutyronitrile)",
      "pel_ppm": "0.5",
      "pel_mgm3": "3",
      "id": "tetramethyl-succinonitrile-decomposition-product-of-2-2-azobisisobutyronitrile",
      "url": "https://referencesource.org/workplace-exposure-limits/tetramethyl-succinonitrile-decomposition-product-of-2-2-azobisisobutyronitrile/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "3333526 | S | Tetramethyl succinonitrile (decomposition product of 2,2\u2032-azobisisobutyronitrile) | 0.5 | 3"
    },
    {
      "substance": "Tetramethyl thiuram disulfide, see Thiram",
      "id": "tetramethyl-thiuram-disulfide-see-thiram",
      "url": "https://referencesource.org/workplace-exposure-limits/tetramethyl-thiuram-disulfide-see-thiram/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "137268 | | Tetramethyl thiuram disulfide, see Thiram"
    },
    {
      "substance": "Tetramethylolmethane; see Pentaerythritol",
      "id": "tetramethylolmethane-see-pentaerythritol",
      "url": "https://referencesource.org/workplace-exposure-limits/tetramethylolmethane-see-pentaerythritol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "115775 | | Tetramethylolmethane; see Pentaerythritol"
    },
    {
      "substance": "Tetranitromethane",
      "cas_number": "509-14-8",
      "pel_ppm": "1",
      "pel_mgm3": "8",
      "id": "tetranitromethane",
      "url": "https://referencesource.org/workplace-exposure-limits/tetranitromethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tetranitromethane | 509-14-8 | 1 | 8 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "1",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Tetranitromethane | 509-14-8 | 1 | 8 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.005",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "509148 | | Tetranitromethane | 0.005 | 0.04",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "8",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Tetranitromethane | 509-14-8 | 1 | 8 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "0.04",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "509148 | | Tetranitromethane | 0.005 | 0.04",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Tetrasodium pyrophosphate",
      "pel_mgm3": "5",
      "id": "tetrasodium-pyrophosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/tetrasodium-pyrophosphate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7722885 | | Tetrasodium pyrophosphate | -- | 5"
    },
    {
      "substance": "Tetryl (2,4,6-Trinitrophenylmethylnitramine)",
      "cas_number": "479-45-8",
      "pel_mgm3": "1.5",
      "id": "tetryl-2-4-6-trinitrophenylmethylnitramine",
      "url": "https://referencesource.org/workplace-exposure-limits/tetryl-2-4-6-trinitrophenylmethylnitramine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tetryl (2,4,6-Trinitrophenylmethylnitramine) | 479-45-8 | - | 1.5 | X |"
    },
    {
      "substance": "Tetryl; 2,4,6-trinitrophenylmethylnitramine",
      "pel_mgm3": "1.5",
      "id": "tetryl-2-4-6-trinitrophenylmethylnitramine-2",
      "url": "https://referencesource.org/workplace-exposure-limits/tetryl-2-4-6-trinitrophenylmethylnitramine-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "479458 | S | Tetryl; 2,4,6-trinitrophenylmethylnitramine | -- | 1.5"
    },
    {
      "substance": "Thallium, soluble compounds (as Tl)",
      "cas_number": "7440-28-0",
      "pel_mgm3": "0.1",
      "id": "thallium-soluble-compounds-as-tl",
      "url": "https://referencesource.org/workplace-exposure-limits/thallium-soluble-compounds-as-tl/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Thallium, soluble compounds (as Tl) | 7440-28-0 | - | 0.1 | X |"
    },
    {
      "substance": "THF; see Tetrahydrofuran",
      "id": "thf-see-tetrahydrofuran",
      "url": "https://referencesource.org/workplace-exposure-limits/thf-see-tetrahydrofuran/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "109999 | | THF; see Tetrahydrofuran"
    },
    {
      "substance": "Thioglycolic acid",
      "pel_ppm": "1",
      "pel_mgm3": "3.8",
      "id": "thioglycolic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/thioglycolic-acid/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "68111 | S | Thioglycolic acid | 1 | 3.8"
    },
    {
      "substance": "Thionyl chloride",
      "pel_ppm": "1",
      "pel_mgm3": "5",
      "ceiling": "C",
      "id": "thionyl-chloride",
      "url": "https://referencesource.org/workplace-exposure-limits/thionyl-chloride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7719097 | | Thionyl chloride | 1 | 5 | C"
    },
    {
      "substance": "Thiram",
      "cas_number": "137-26-8",
      "pel_mgm3": "5",
      "id": "thiram",
      "url": "https://referencesource.org/workplace-exposure-limits/thiram/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Thiram | 137-26-8 | - | 5 | - |"
    },
    {
      "substance": "Thiram; bis(dimethylthiocarbamoyl) disulfide",
      "pel_mgm3": "5",
      "id": "thiram-bis-dimethylthiocarbamoyl-disulfide",
      "url": "https://referencesource.org/workplace-exposure-limits/thiram-bis-dimethylthiocarbamoyl-disulfide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "137268 | | Thiram; bis(dimethylthiocarbamoyl) disulfide | -- | 5"
    },
    {
      "substance": "Tin, inorganic compounds (except oxides) (as Sn)",
      "cas_number": "7440-31-5",
      "pel_mgm3": "2",
      "id": "tin-inorganic-compounds-except-oxides-as-sn",
      "url": "https://referencesource.org/workplace-exposure-limits/tin-inorganic-compounds-except-oxides-as-sn/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tin, inorganic compounds (except oxides) (as Sn) | 7440-31-5 | - | 2 | - |"
    },
    {
      "substance": "Tin, organic compounds (as Sn)",
      "cas_number": "7440-31-5",
      "pel_mgm3": "0.1",
      "id": "tin-organic-compounds-as-sn",
      "url": "https://referencesource.org/workplace-exposure-limits/tin-organic-compounds-as-sn/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tin, organic compounds (as Sn) | 7440-31-5 | - | 0.1 | - |"
    },
    {
      "substance": "Tin, tin oxide and inorganic compounds, except SnH $4 , as Sn",
      "pel_mgm3": "2",
      "id": "tin-tin-oxide-and-inorganic-compounds-except-snh-4-as-sn",
      "url": "https://referencesource.org/workplace-exposure-limits/tin-tin-oxide-and-inorganic-compounds-except-snh-4-as-sn/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "21651194 | | Tin, tin oxide and inorganic compounds, except SnH $4 , as Sn | -- | 2"
    },
    {
      "substance": "Titanium dioxide",
      "cas_number": "13463-67-7",
      "id": "titanium-dioxide",
      "url": "https://referencesource.org/workplace-exposure-limits/titanium-dioxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Titanium dioxide | 13463-67-7 | - | - | - |"
    },
    {
      "substance": "Titanium dioxide, as Ti; see Particulates not otherwise regulated",
      "id": "titanium-dioxide-as-ti-see-particulates-not-otherwise-regulated",
      "url": "https://referencesource.org/workplace-exposure-limits/titanium-dioxide-as-ti-see-particulates-not-otherwise-regulated/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "13463677 | | Titanium dioxide, as Ti; see Particulates not otherwise regulated"
    },
    {
      "substance": "TMTD; see Thiram",
      "id": "tmtd-see-thiram",
      "url": "https://referencesource.org/workplace-exposure-limits/tmtd-see-thiram/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "137268 | | TMTD; see Thiram"
    },
    {
      "substance": "TNT; see 2,4,6-Trinitrotoluene",
      "id": "tnt-see-2-4-6-trinitrotoluene",
      "url": "https://referencesource.org/workplace-exposure-limits/tnt-see-2-4-6-trinitrotoluene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "118967 | | TNT; see 2,4,6-Trinitrotoluene"
    },
    {
      "substance": "Toluene",
      "cas_number": "108-88-3",
      "id": "toluene",
      "url": "https://referencesource.org/workplace-exposure-limits/toluene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Toluene | 108-88-3 | - | ( 2 ) | - |"
    },
    {
      "substance": "Toluene-2,4-diisocyanate (TDI)",
      "cas_number": "584-84-9",
      "pel_ppm": "(C)0.02",
      "pel_mgm3": "(C)0.14",
      "id": "toluene-2-4-diisocyanate-tdi",
      "url": "https://referencesource.org/workplace-exposure-limits/toluene-2-4-diisocyanate-tdi/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Toluene-2,4-diisocyanate (TDI) | 584-84-9 | (C)0.02 | (C)0.14 | - |"
    },
    {
      "substance": "Toluene-2,4-diisocyanate; TDI",
      "pel_ppm": "0.005",
      "pel_mgm3": "0.04",
      "ceiling": "0.02 ppm",
      "stel_ppm": "0.02",
      "stel_mgm3": "0.15",
      "id": "toluene-2-4-diisocyanate-tdi-2",
      "url": "https://referencesource.org/workplace-exposure-limits/toluene-2-4-diisocyanate-tdi-2/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "584849 | | Toluene-2,4-diisocyanate; TDI | 0.005 | 0.04 | 0.02 ppm | 0.02 | 0.15"
    },
    {
      "substance": "Toluene; toluol",
      "pel_ppm": "10",
      "pel_mgm3": "37",
      "ceiling": "500 ppm",
      "stel_ppm": "150",
      "stel_mgm3": "560",
      "id": "toluene-toluol",
      "url": "https://referencesource.org/workplace-exposure-limits/toluene-toluol/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108883 | S | Toluene; toluol | 10 | 37 | 500 ppm | 150 | 560"
    },
    {
      "substance": "Toxaphene; see Chlorinated camphene",
      "id": "toxaphene-see-chlorinated-camphene",
      "url": "https://referencesource.org/workplace-exposure-limits/toxaphene-see-chlorinated-camphene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "8001352 | | Toxaphene; see Chlorinated camphene"
    },
    {
      "substance": "Tpp; see Triphenyl phosphate",
      "id": "tpp-see-triphenyl-phosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/tpp-see-triphenyl-phosphate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "115866 | | Tpp; see Triphenyl phosphate"
    },
    {
      "substance": "Tribromomethane; see Bromoform",
      "id": "tribromomethane-see-bromoform",
      "url": "https://referencesource.org/workplace-exposure-limits/tribromomethane-see-bromoform/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75252 | | Tribromomethane; see Bromoform"
    },
    {
      "substance": "Tributyl phosphate",
      "cas_number": "126-73-8",
      "pel_mgm3": "5",
      "id": "tributyl-phosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/tributyl-phosphate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tributyl phosphate | 126-73-8 | - | 5 | - |",
      "disagreements": [
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "5",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Tributyl phosphate | 126-73-8 | - | 5 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "2.5",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "126738 | | Tributyl phosphate | 0.2 | 2.5",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Trichloroacetic acid",
      "pel_ppm": "1",
      "pel_mgm3": "5",
      "id": "trichloroacetic-acid",
      "url": "https://referencesource.org/workplace-exposure-limits/trichloroacetic-acid/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "76039 | | Trichloroacetic acid | 1 | 5"
    },
    {
      "substance": "Trichloroethylene",
      "cas_number": "79-01-6",
      "id": "trichloroethylene",
      "url": "https://referencesource.org/workplace-exposure-limits/trichloroethylene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Trichloroethylene | 79-01-6 | - | ( 2 ) | - |"
    },
    {
      "substance": "Trichloroethylene; trichloro-ethene",
      "pel_ppm": "25",
      "pel_mgm3": "135",
      "ceiling": "300 ppm",
      "stel_ppm": "100",
      "stel_mgm3": "537",
      "id": "trichloroethylene-trichloro-ethene",
      "url": "https://referencesource.org/workplace-exposure-limits/trichloroethylene-trichloro-ethene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "79016 | | Trichloroethylene; trichloro-ethene | 25 | 135 | 300 ppm | 100 | 537"
    },
    {
      "substance": "Trichlorofluoromethane; Fluorocarbon 11",
      "pel_ppm": "1,000",
      "pel_mgm3": "5,600",
      "ceiling": "C",
      "id": "trichlorofluoromethane-fluorocarbon-11",
      "url": "https://referencesource.org/workplace-exposure-limits/trichlorofluoromethane-fluorocarbon-11/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75694 | | Trichlorofluoromethane; Fluorocarbon 11 | 1,000 | 5,600 | C"
    },
    {
      "substance": "Trichloromethane; see Chloroform",
      "id": "trichloromethane-see-chloroform",
      "url": "https://referencesource.org/workplace-exposure-limits/trichloromethane-see-chloroform/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "67663 | | Trichloromethane; see Chloroform"
    },
    {
      "substance": "Trichloromethanethiol; see Perchloromethyl mercaptan",
      "id": "trichloromethanethiol-see-perchloromethyl-mercaptan",
      "url": "https://referencesource.org/workplace-exposure-limits/trichloromethanethiol-see-perchloromethyl-mercaptan/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "594423 | | Trichloromethanethiol; see Perchloromethyl mercaptan"
    },
    {
      "substance": "Trichloronaphthalene",
      "cas_number": "1321-65-9",
      "pel_mgm3": "5",
      "id": "trichloronaphthalene",
      "url": "https://referencesource.org/workplace-exposure-limits/trichloronaphthalene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Trichloronaphthalene | 1321-65-9 | - | 5 | X |",
      "disagreements": []
    },
    {
      "substance": "Trichloronitromethane; see Chloropicrin",
      "id": "trichloronitromethane-see-chloropicrin",
      "url": "https://referencesource.org/workplace-exposure-limits/trichloronitromethane-see-chloropicrin/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "76062 | | Trichloronitromethane; see Chloropicrin"
    },
    {
      "substance": "Tricresyl phosphate; see Triorthocresyl phosphate",
      "id": "tricresyl-phosphate-see-triorthocresyl-phosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/tricresyl-phosphate-see-triorthocresyl-phosphate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "78308 | | Tricresyl phosphate; see Triorthocresyl phosphate"
    },
    {
      "substance": "Tricyclohexyltin hydroxide; see Cyhexatin",
      "id": "tricyclohexyltin-hydroxide-see-cyhexatin",
      "url": "https://referencesource.org/workplace-exposure-limits/tricyclohexyltin-hydroxide-see-cyhexatin/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "13121705 | | Tricyclohexyltin hydroxide; see Cyhexatin"
    },
    {
      "substance": "Tridymite,",
      "pel_mgm3": "0.05",
      "id": "tridymite",
      "url": "https://referencesource.org/workplace-exposure-limits/tridymite/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "15468323 | | Tridymite, | -- | 0.05"
    },
    {
      "substance": "Tridymite; see 1910.1053 7",
      "cas_number": "15468-32-3",
      "id": "tridymite-see-1910-1053-7",
      "url": "https://referencesource.org/workplace-exposure-limits/tridymite-see-1910-1053-7/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tridymite; see 1910.1053 7 | 15468-32-3 | - | - | - |"
    },
    {
      "substance": "Triethanolamine",
      "pel_mgm3": "5",
      "id": "triethanolamine",
      "url": "https://referencesource.org/workplace-exposure-limits/triethanolamine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "102716 | | Triethanolamine | -- | 5"
    },
    {
      "substance": "Triethylamine",
      "cas_number": "121-44-8",
      "pel_ppm": "25",
      "pel_mgm3": "100",
      "id": "triethylamine",
      "url": "https://referencesource.org/workplace-exposure-limits/triethylamine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Triethylamine | 121-44-8 | 25 | 100 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "25",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Triethylamine | 121-44-8 | 25 | 100 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "121448 | S | Triethylamine | 1 | 4.1 | C",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "100",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Triethylamine | 121-44-8 | 25 | 100 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "4.1",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "121448 | S | Triethylamine | 1 | 4.1 | C",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Triethylene glycol dimethyl ether, Triglyme",
      "pel_ppm": "5",
      "pel_mgm3": "36",
      "id": "triethylene-glycol-dimethyl-ether-triglyme",
      "url": "https://referencesource.org/workplace-exposure-limits/triethylene-glycol-dimethyl-ether-triglyme/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "112492 | S | Triethylene glycol dimethyl ether, Triglyme | 5 | 36"
    },
    {
      "substance": "Trifluorobromomethane",
      "cas_number": "75-63-8",
      "pel_ppm": "1000",
      "pel_mgm3": "6100",
      "id": "trifluorobromomethane",
      "url": "https://referencesource.org/workplace-exposure-limits/trifluorobromomethane/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Trifluorobromomethane | 75-63-8 | 1000 | 6100 | - |",
      "disagreements": [
        {
          "field": "pel_ppm",
          "versions": [
            {
              "value": "1000",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Trifluorobromomethane | 75-63-8 | 1000 | 6100 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "1,000",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "75638 | | Trifluorobromomethane | 1,000 | 6,100",
              "as_of": "2026-08-05"
            }
          ]
        },
        {
          "field": "pel_mgm3",
          "versions": [
            {
              "value": "6100",
              "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
              "source_quote": "Trifluorobromomethane | 75-63-8 | 1000 | 6100 | - |",
              "as_of": "2026-08-05"
            },
            {
              "value": "6,100",
              "source": "https://www.dir.ca.gov/title8/5155.html",
              "source_quote": "75638 | | Trifluorobromomethane | 1,000 | 6,100",
              "as_of": "2026-08-05"
            }
          ]
        }
      ]
    },
    {
      "substance": "Trimellitic anhydride",
      "pel_ppm": "0.005",
      "pel_mgm3": "0.04",
      "ceiling": "C",
      "id": "trimellitic-anhydride",
      "url": "https://referencesource.org/workplace-exposure-limits/trimellitic-anhydride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "552307 | | Trimellitic anhydride | 0.005 | 0.04 | C"
    },
    {
      "substance": "Trimethyl phosphite",
      "pel_ppm": "2",
      "pel_mgm3": "10",
      "id": "trimethyl-phosphite",
      "url": "https://referencesource.org/workplace-exposure-limits/trimethyl-phosphite/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "121459 | | Trimethyl phosphite | 2 | 10"
    },
    {
      "substance": "Trimethylamine",
      "pel_ppm": "5",
      "pel_mgm3": "12",
      "stel_ppm": "15",
      "stel_mgm3": "36",
      "id": "trimethylamine",
      "url": "https://referencesource.org/workplace-exposure-limits/trimethylamine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75503 | | Trimethylamine | 5 | 12 | | 15 | 36"
    },
    {
      "substance": "Triorthocresyl phosphate",
      "cas_number": "78-30-8",
      "pel_mgm3": "0.1",
      "id": "triorthocresyl-phosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/triorthocresyl-phosphate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Triorthocresyl phosphate | 78-30-8 | - | 0.1 | - |",
      "disagreements": []
    },
    {
      "substance": "Triphenyl phosphate",
      "cas_number": "115-86-6",
      "pel_mgm3": "3",
      "id": "triphenyl-phosphate",
      "url": "https://referencesource.org/workplace-exposure-limits/triphenyl-phosphate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Triphenyl phosphate | 115-86-6 | - | 3 | - |"
    },
    {
      "substance": "Triphenyl phosphate; TPP",
      "pel_mgm3": "3",
      "id": "triphenyl-phosphate-tpp",
      "url": "https://referencesource.org/workplace-exposure-limits/triphenyl-phosphate-tpp/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "115866 | S | Triphenyl phosphate; TPP | -- | 3"
    },
    {
      "substance": "Triphenylamine",
      "pel_mgm3": "5",
      "id": "triphenylamine",
      "url": "https://referencesource.org/workplace-exposure-limits/triphenylamine/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "603349 | | Triphenylamine | -- | 5"
    },
    {
      "substance": "Tripoli, (as quartz)",
      "pel_mgm3": "0.05",
      "id": "tripoli-as-quartz",
      "url": "https://referencesource.org/workplace-exposure-limits/tripoli-as-quartz/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1317959 | | Tripoli, (as quartz) | -- | 0.05"
    },
    {
      "substance": "Tripoli (as quartz); see 1910.1053 7",
      "cas_number": "1317-95-9",
      "id": "tripoli-as-quartz-see-1910-1053-7",
      "url": "https://referencesource.org/workplace-exposure-limits/tripoli-as-quartz-see-1910-1053-7/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Tripoli (as quartz); see 1910.1053 7 | 1317-95-9 | - | - | - |"
    },
    {
      "substance": "Tungsten metal, as W",
      "pel_mgm3": "5",
      "id": "tungsten-metal-as-w",
      "url": "https://referencesource.org/workplace-exposure-limits/tungsten-metal-as-w/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "7440337 | | Tungsten metal, as W | -- | 5"
    },
    {
      "substance": "Turpentine",
      "cas_number": "8006-64-2",
      "pel_ppm": "100",
      "pel_mgm3": "560",
      "id": "turpentine",
      "url": "https://referencesource.org/workplace-exposure-limits/turpentine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Turpentine | 8006-64-2 | 100 | 560 | - |",
      "disagreements": []
    },
    {
      "substance": "Uranium (as U)",
      "cas_number": "7440-61-1",
      "id": "uranium-as-u",
      "url": "https://referencesource.org/workplace-exposure-limits/uranium-as-u/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Uranium (as U) | 7440-61-1 | - | - | - |"
    },
    {
      "substance": "Valeraldehyde",
      "pel_ppm": "50",
      "pel_mgm3": "175",
      "id": "valeraldehyde",
      "url": "https://referencesource.org/workplace-exposure-limits/valeraldehyde/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "110623 | | Valeraldehyde | 50 | 175"
    },
    {
      "substance": "Vanadium",
      "cas_number": "1314-62-1",
      "id": "vanadium",
      "url": "https://referencesource.org/workplace-exposure-limits/vanadium/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Vanadium | 1314-62-1 | - | - | - |"
    },
    {
      "substance": "Vanadium pentoxide (V $2 O $5 ), respirable dust and fume",
      "pel_mgm3": "0.05",
      "id": "vanadium-pentoxide-v-2-o-5-respirable-dust-and-fume",
      "url": "https://referencesource.org/workplace-exposure-limits/vanadium-pentoxide-v-2-o-5-respirable-dust-and-fume/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1314621 | | Vanadium pentoxide (V $2 O $5 ), respirable dust and fume | -- | 0.05"
    },
    {
      "substance": "VC; see Vinyl chloride, Section 5210",
      "id": "vc-see-vinyl-chloride-section-5210",
      "url": "https://referencesource.org/workplace-exposure-limits/vc-see-vinyl-chloride-section-5210/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75014 | S | VC; see Vinyl chloride, Section 5210"
    },
    {
      "substance": "Vinyl acetate",
      "pel_ppm": "10",
      "pel_mgm3": "30",
      "stel_ppm": "15",
      "stel_mgm3": "45",
      "id": "vinyl-acetate",
      "url": "https://referencesource.org/workplace-exposure-limits/vinyl-acetate/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "108054 | | Vinyl acetate | 10 | 30 | | 15 | 45"
    },
    {
      "substance": "Vinyl bromide; bromoethylene",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.44",
      "id": "vinyl-bromide-bromoethylene",
      "url": "https://referencesource.org/workplace-exposure-limits/vinyl-bromide-bromoethylene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "593602 | | Vinyl bromide; bromoethylene | 0.1 | 0.44"
    },
    {
      "substance": "Vinyl chloride; see 1910.1017",
      "cas_number": "75-01-4",
      "id": "vinyl-chloride-see-1910-1017",
      "url": "https://referencesource.org/workplace-exposure-limits/vinyl-chloride-see-1910-1017/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Vinyl chloride; see 1910.1017 | 75-01-4 | - | - | - |"
    },
    {
      "substance": "Vinyl chloride, see Section 5210",
      "pel_ppm": "1",
      "id": "vinyl-chloride-see-section-5210",
      "url": "https://referencesource.org/workplace-exposure-limits/vinyl-chloride-see-section-5210/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75014 | S | Vinyl chloride, see Section 5210 | 1"
    },
    {
      "substance": "Vinyl cyanide, see Acrylonitrile, Section 5213",
      "id": "vinyl-cyanide-see-acrylonitrile-section-5213",
      "url": "https://referencesource.org/workplace-exposure-limits/vinyl-cyanide-see-acrylonitrile-section-5213/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "107131 | S | Vinyl cyanide, see Acrylonitrile, Section 5213"
    },
    {
      "substance": "Vinyl cyclohexene dioxide",
      "pel_ppm": "0.1",
      "pel_mgm3": "0.57",
      "id": "vinyl-cyclohexene-dioxide",
      "url": "https://referencesource.org/workplace-exposure-limits/vinyl-cyclohexene-dioxide/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "106876 | S | Vinyl cyclohexene dioxide | 0.1 | 0.57"
    },
    {
      "substance": "Vinyl fluoride",
      "pel_ppm": "0.2",
      "pel_mgm3": "0.38",
      "id": "vinyl-fluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/vinyl-fluoride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75025 | | Vinyl fluoride | 0.2 | 0.38"
    },
    {
      "substance": "Vinyl toluene",
      "cas_number": "25013-15-4",
      "pel_ppm": "100",
      "pel_mgm3": "480",
      "id": "vinyl-toluene",
      "url": "https://referencesource.org/workplace-exposure-limits/vinyl-toluene/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Vinyl toluene | 25013-15-4 | 100 | 480 | - |"
    },
    {
      "substance": "Vinylbenzene; see Styrene",
      "id": "vinylbenzene-see-styrene",
      "url": "https://referencesource.org/workplace-exposure-limits/vinylbenzene-see-styrene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "100425 | | Vinylbenzene; see Styrene"
    },
    {
      "substance": "Vinylidene chloride; 1,1-dichloroethylene",
      "pel_ppm": "1",
      "pel_mgm3": "4",
      "id": "vinylidene-chloride-1-1-dichloroethylene",
      "url": "https://referencesource.org/workplace-exposure-limits/vinylidene-chloride-1-1-dichloroethylene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75354 | | Vinylidene chloride; 1,1-dichloroethylene | 1 | 4"
    },
    {
      "substance": "Vinylidene fluoride",
      "pel_ppm": "100",
      "pel_mgm3": "262",
      "id": "vinylidene-fluoride",
      "url": "https://referencesource.org/workplace-exposure-limits/vinylidene-fluoride/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "75387 | | Vinylidene fluoride | 100 | 262"
    },
    {
      "substance": "Vinyltoluene",
      "pel_ppm": "50",
      "pel_mgm3": "240",
      "id": "vinyltoluene",
      "url": "https://referencesource.org/workplace-exposure-limits/vinyltoluene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "25013154 | | Vinyltoluene | 50 | 240"
    },
    {
      "substance": "VM & P (Varnish Makers and Painters) Naphtha",
      "pel_ppm": "300",
      "pel_mgm3": "1,350",
      "stel_ppm": "400",
      "stel_mgm3": "1800",
      "id": "vm-p-varnish-makers-and-painters-naphtha",
      "url": "https://referencesource.org/workplace-exposure-limits/vm-p-varnish-makers-and-painters-naphtha/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "8030306 | | VM & P (Varnish Makers and Painters) Naphtha | 300 | 1,350 | | 400 | 1800"
    },
    {
      "substance": "Warfarin",
      "cas_number": "81-81-2",
      "pel_mgm3": "0.1",
      "id": "warfarin",
      "url": "https://referencesource.org/workplace-exposure-limits/warfarin/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Warfarin | 81-81-2 | - | 0.1 | - |"
    },
    {
      "substance": "Warfarin; 3-(alpha-acetonyl-benzyl)-4-hydroxycoumarin",
      "pel_mgm3": "0.1",
      "id": "warfarin-3-alpha-acetonyl-benzyl-4-hydroxycoumarin",
      "url": "https://referencesource.org/workplace-exposure-limits/warfarin-3-alpha-acetonyl-benzyl-4-hydroxycoumarin/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "81812 | | Warfarin; 3-(alpha-acetonyl-benzyl)-4-hydroxycoumarin | -- | 0.1"
    },
    {
      "substance": "Xylene; xylol; dimethylbenzene",
      "pel_ppm": "100",
      "pel_mgm3": "435",
      "ceiling": "300 ppm",
      "stel_ppm": "150",
      "stel_mgm3": "655",
      "id": "xylene-xylol-dimethylbenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/xylene-xylol-dimethylbenzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1330207 | | Xylene; xylol; dimethylbenzene | 100 | 435 | 300 ppm | 150 | 655"
    },
    {
      "substance": "Xylenes (o-, m-, p-isomers)",
      "cas_number": "1330-20-7",
      "pel_ppm": "100",
      "pel_mgm3": "435",
      "id": "xylenes-o-m-p-isomers",
      "url": "https://referencesource.org/workplace-exposure-limits/xylenes-o-m-p-isomers/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Xylenes (o-, m-, p-isomers) | 1330-20-7 | 100 | 435 | - |"
    },
    {
      "substance": "Xylidine",
      "cas_number": "1300-73-8",
      "pel_ppm": "5",
      "pel_mgm3": "25",
      "id": "xylidine",
      "url": "https://referencesource.org/workplace-exposure-limits/xylidine/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Xylidine | 1300-73-8 | 5 | 25 | X |"
    },
    {
      "substance": "Xylidine; aminodimethylbenzene",
      "pel_ppm": "0.5",
      "pel_mgm3": "2.5",
      "id": "xylidine-aminodimethylbenzene",
      "url": "https://referencesource.org/workplace-exposure-limits/xylidine-aminodimethylbenzene/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "1300738 | S | Xylidine; aminodimethylbenzene | 0.5 | 2.5"
    },
    {
      "substance": "Yttrium",
      "cas_number": "7440-65-5",
      "pel_mgm3": "1",
      "id": "yttrium",
      "url": "https://referencesource.org/workplace-exposure-limits/yttrium/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Yttrium | 7440-65-5 | - | 1 | - |"
    },
    {
      "substance": "Zinc chloride fume",
      "cas_number": "7646-85-7",
      "pel_mgm3": "1",
      "id": "zinc-chloride-fume",
      "url": "https://referencesource.org/workplace-exposure-limits/zinc-chloride-fume/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Zinc chloride fume | 7646-85-7 | - | 1 | - |",
      "disagreements": []
    },
    {
      "substance": "Zinc chromate, as Cr",
      "pel_mgm3": "0.005",
      "id": "zinc-chromate-as-cr",
      "url": "https://referencesource.org/workplace-exposure-limits/zinc-chromate-as-cr/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "13530659 | | Zinc chromate, as Cr | -- | 0.005"
    },
    {
      "substance": "Zinc chromate hydroxide, as Cr",
      "pel_mgm3": "0.005",
      "id": "zinc-chromate-hydroxide-as-cr",
      "url": "https://referencesource.org/workplace-exposure-limits/zinc-chromate-hydroxide-as-cr/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "15930946 | | Zinc chromate hydroxide, as Cr | -- | 0.005"
    },
    {
      "substance": "Zinc oxide",
      "cas_number": "1314-13-2",
      "id": "zinc-oxide",
      "url": "https://referencesource.org/workplace-exposure-limits/zinc-oxide/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Zinc oxide | 1314-13-2 | - | - | - |"
    },
    {
      "substance": "Zinc oxide fume",
      "cas_number": "1314-13-2",
      "pel_mgm3": "5",
      "id": "zinc-oxide-fume",
      "url": "https://referencesource.org/workplace-exposure-limits/zinc-oxide-fume/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Zinc oxide fume | 1314-13-2 | - | 5 | - |",
      "disagreements": []
    },
    {
      "substance": "Zinc potassium chromate, as Cr",
      "pel_mgm3": "0.005",
      "id": "zinc-potassium-chromate-as-cr",
      "url": "https://referencesource.org/workplace-exposure-limits/zinc-potassium-chromate-as-cr/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "11103869 | | Zinc potassium chromate, as Cr | -- | 0.005"
    },
    {
      "substance": "Zinc stearate",
      "cas_number": "557-05-1",
      "id": "zinc-stearate",
      "url": "https://referencesource.org/workplace-exposure-limits/zinc-stearate/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Zinc stearate | 557-05-1 | - | - | - |",
      "disagreements": []
    },
    {
      "substance": "Zinc yellow, as Cr",
      "pel_mgm3": "0.005",
      "id": "zinc-yellow-as-cr",
      "url": "https://referencesource.org/workplace-exposure-limits/zinc-yellow-as-cr/",
      "source": "https://www.dir.ca.gov/title8/5155.html",
      "source_quote": "37300235 | | Zinc yellow, as Cr | -- | 0.005"
    },
    {
      "substance": "Zirconium compounds (as Zr)",
      "cas_number": "7440-67-7",
      "pel_mgm3": "5",
      "id": "zirconium-compounds-as-zr",
      "url": "https://referencesource.org/workplace-exposure-limits/zirconium-compounds-as-zr/",
      "source": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1",
      "source_quote": "Zirconium compounds (as Zr) | 7440-67-7 | - | 5 | - |"
    }
  ]
}