Records 401–800 — US workplace chemical exposure limits: federal OSHA, Cal/OSHA and NIOSH, side by side

Records 401 to 800 of 1,030. Each links to its own page, which carries the source URL and the quoted line that states the value.

• Diphenylmethane diisocyanate; see Methylene bis(phenylisocyanate)101688 | | Diphenylmethane diisocyanate; see Methylene bis(phenylisocyanate)
• Dipropyl ketone123193 | | Dipropyl ketone | 50 | 235
• Dipropylene glycol methyl etherDipropylene glycol methyl ether | 34590-94-8 | 100 | 600 | X |
• Diquat; 1,1'-ethylene-2,2'-dipyridinium dibromide85007 | | Diquat; 1,1'-ethylene-2,2'-dipyridinium dibromide | --
• Disulfiram97778 | | Disulfiram | -- | 2
• DisulfotonNIOSH REL TWA 0.1 mg/m3 [skin]
• Diuron330541 | | Diuron | -- | 10
• Divinyl benzene1321740 | | Divinyl benzene | 10 | 50
• DMF; see Dimethylformamide68122 | | DMF; see Dimethylformamide
• DMH; see 1,1-Dimethylhydrazine57147 | | DMH; see 1,1-Dimethylhydrazine
• EmeryEmery | 12415-34-8 | - | - | - |
• EmeryNIOSH REL See Appendix D
• EndosulfanNIOSH REL TWA 0.1 mg/m3 [skin]
• EndrinEndrin | 72-20-8 | - | 0.1 | X |
• Enflurane13838169 | | Enflurane | 2 | 15
• EpichlorohydrinEpichlorohydrin | 106-89-8 | 5 | 19 | X |
• Epichlorohydrin; 1-chloro-2, 3-epoxypropane106898 | S | Epichlorohydrin; 1-chloro-2, 3-epoxypropane | 0.05 | 0.19
• EPNEPN | 2104-64-5 | - | 0.5 | X |
• Ethane74840 | | Ethane | (h) | --
• Ethanethiol; see Ethyl mercaptan75081 | | Ethanethiol; see Ethyl mercaptan
• Ethanol; see Ethyl alcohol64175 | | Ethanol; see Ethyl alcohol
• EthanolamineEthanolamine | 141-43-5 | 3 | 6 | - |
• Ethanolamine; 2-aminoethanol141435 | | Ethanolamine; 2-aminoethanol | 3 | 8 | | 6 | 15
• Ethion563122 | S | Ethion | -- | 0.4
• Ethyl acetateEthyl acetate | 141-78-6 | 400 | 1400 | - |
• Ethyl acrylateEthyl acrylate | 140-88-5 | 25 | 100 | X |
• Ethyl alcoholNIOSH REL TWA 1000 ppm (1900 mg/m3)
• Ethyl alcohol (Ethanol)Ethyl alcohol (Ethanol) | 64-17-5 | 1000 | 1900 | - |
• Ethyl alcohol; ethanol64175 | | Ethyl alcohol; ethanol | 1,000 | 1,900
• Ethyl benzeneEthyl benzene | 100-41-4 | 100 | 435 | - |
• Ethyl bromideEthyl bromide | 74-96-4 | 200 | 890 | - |
• Ethyl butyl ketoneNIOSH REL TWA 50 ppm (230 mg/m3)
• Ethyl chlorideEthyl chloride | 75-00-3 | 1000 | 2600 | - |
• Ethyl chloride; chloroethane75003 | S | Ethyl chloride; chloroethane | 100 | 264
• Ethyl cyanoacrylate7085850 | | Ethyl cyanoacrylate | 0.2 | 1.02
• Ethyl etherEthyl ether | 60-29-7 | 400 | 1200 | - |
• Ethyl formateEthyl formate | 109-94-4 | 100 | 300 | - |
• Ethyl mercaptanEthyl mercaptan | 75-08-1 | (C)10 | (C)25 | - |
• Ethyl mercaptan; ethanethiol75081 | | Ethyl mercaptan; ethanethiol | 0.5 | 1
• Ethyl methyl ketone; see Methyl ethyl ketone78933 | | Ethyl methyl ketone; see Methyl ethyl ketone
• Ethyl silicateEthyl silicate | 78-10-4 | 100 | 850 | - |
• Ethyl tert-butyl ether637923 | | Ethyl tert-butyl ether | 5 | 21
• EthylamineEthylamine | 75-04-7 | 10 | 18 | - |
• Ethylene74851 | | Ethylene | (h) | --
• Ethylene chlorohydrinEthylene chlorohydrin | 107-07-3 | 5 | 16 | X |
• Ethylene chlorohydrin; 2-chloroethanol107073 | S | Ethylene chlorohydrin; 2-chloroethanol | 1 | 3 | C
• Ethylene dibromideEthylene dibromide | 106-93-4 | - | (2) | - |
• Ethylene dibromide; 1,2-dibromoethane, see Section 5219106934 | S | Ethylene dibromide; 1,2-dibromoethane, see Section 5219 | 0.13 | 1 | C
• Ethylene dichlorideNIOSH REL Ca TWA 1 ppm (4 mg/m3) ST 2 ppm (8 mg/m3)
• Ethylene dichloride (1,2-Dichloroethane)Ethylene dichloride (1,2-Dichloroethane) | 107-06-2 | - | (2) | - |
• Ethylene dichloride; 1,2-dichloroethane107062 | | Ethylene dichloride; 1,2-dichloroethane | 1 | 4 | 200 ppm | 2 | 8
• Ethylene glycolNIOSH REL See Appendix D
• Ethylene glycol diethyl ether, 1,2-diethoxyethane629141 | S | Ethylene glycol diethyl ether, 1,2-diethoxyethane | 5 | 24
• Ethylene glycol dimethyl ether, 1,2-dimethoxyethane, Glyme110714 | S | Ethylene glycol dimethyl ether, 1,2-dimethoxyethane, Glyme | 1 | 3.7 | | 5 | 18
• Ethylene glycol dinitrateEthylene glycol dinitrate | 628-96-6 | (C)0.2 | (C)1 | X |
• Ethylene glycol monoethyl ether, see 2-Ethoxyethanol110805 | S | Ethylene glycol monoethyl ether, see 2-Ethoxyethanol
• Ethylene glycol monomethyl ether acetate; see 2-Methoxyethyl acetate110496 | S | Ethylene glycol monomethyl ether acetate; see 2-Methoxyethyl acetate
• Ethylene glycol monomethyl ether, see 2-Methoxyethanol109864 | S | Ethylene glycol monomethyl ether, see 2-Methoxyethanol
• Ethylene oxideNIOSH REL Ca TWA <0.1 ppm (0.18 mg/m3) C 5 ppm (9 mg/m3) [10-min/day]
• Ethylene thioureaNIOSH REL Ca Use encapsulated form. See Appendix A
• EthylenediamineEthylenediamine | 107-15-3 | 10 | 25 | - |
• Ethylenediamine; 1,2-diaminoethane107153 | | Ethylenediamine; 1,2-diaminoethane | 10 | 25
• EthyleneimineNIOSH REL Ca See Appendix A
• Ethylidene chloride; see 1,1-Dichloroethane75343 | | Ethylidene chloride; see 1,1-Dichloroethane
• Ethylidene norbornene16219753 | | Ethylidene norbornene | 5 | 25 | C
• Fenamiphos22224926 | S | Fenamiphos | | 0.1
• Fensulfothion115902 | | Fensulfothion | -- | 0.1
• Fenthion55389 | S | Fenthion | -- | 0.2
• FerbamFerbam | 14484-64-1 | - | - | - |
• Ferrovanadium dustFerrovanadium dust | 12604-58-9 | - | 1 | - |
• Fibrous glass, see Glass14808607 | | Fibrous glass, see Glass
• FluorineFluorine | 7782-41-4 | 0.1 | 0.2 | - |
• Fluorocarbon 11; see Trichlorofluoromethane75694 | | Fluorocarbon 11; see Trichlorofluoromethane
• Fluorocarbon 12; see Dichlorodifluoromethane75718 | | Fluorocarbon 12; see Dichlorodifluoromethane
• Fluorocarbon 21; see Dichlorofluoromethane75434 | | Fluorocarbon 21; see Dichlorofluoromethane
• Fluorocarbon 22; see Chlorodifluoromethane75456 | | Fluorocarbon 22; see Chlorodifluoromethane
• Fluorocarbon 112; see 1,1,2,2-Tetrachloro-1,2-difluoroethane76120 | | Fluorocarbon 112; see 1,1,2,2-Tetrachloro-1,2-difluoroethane
• Fluorocarbon 113; see 1,1,2-Trichloro-1,2,2-trifluoroethane76131 | | Fluorocarbon 113; see 1,1,2-Trichloro-1,2,2-trifluoroethane
• FluorotrichloromethaneNIOSH REL C 1000 ppm (5600 mg/m3)
• Fluorotrichloromethane; see Trichlorofluoromethane75694 | | Fluorotrichloromethane; see Trichlorofluoromethane
• Fluorotrichloromethane (Trichlorofluoromethane)Fluorotrichloromethane (Trichlorofluoromethane) | 75-69-4 | 1000 | 5600 | - |
• FluoroxeneNIOSH REL C 2 ppm (10.3 mg/m3) [60-minute]
• Fonofos944229 | S | Fonofos | -- | 0.1
• FormaldehydeNIOSH REL Ca TWA 0.016 ppm C 0.1 ppm [15-minute]
• Formamide75127 | S | Formamide | 10 | 18
• Formic acidFormic acid | 64-18-6 | 5 | 9 | - |
• FurfuralFurfural | 98-01-1 | 5 | 20 | X |
• Furfuryl alcoholFurfuryl alcohol | 98-00-0 | 50 | 200 | - |
• Gasoline8006619 | | Gasoline | 300 | 900 | | 500 | 1500
• Germanium tetrahydride7782652 | | Germanium tetrahydride | 0.2 | 0.6
• GlutaraldehydeNIOSH REL C 0.2 ppm (0.8 mg/m3)
• Glycerin (mist)Glycerin (mist) | 56-81-5 | - | - | - |
• Glyceryl stearate123944 | | Glyceryl stearate | -- | 10
• GlycidolGlycidol | 556-52-5 | 50 | 150 | - |
• Glycidol; 2,3-epoxy-1-propanol556525 | | Glycidol; 2,3-epoxy-1-propanol | 2 | 6.1
• Glycol monobutyl ether; see 2-Butoxyethanol111762 | | Glycol monobutyl ether; see 2-Butoxyethanol
• Glycol monoethyl ether; see 2-Ethoxyethanol110805 | | Glycol monoethyl ether; see 2-Ethoxyethanol
• Glycol monomethyl ether; see 2-Methoxyethanol109864 | | Glycol monomethyl ether; see 2-Methoxyethanol
• GlycolonitrileNIOSH REL C 2 ppm (5 mg/m3) [15-minute]
• Glyoxal, 1,2-ethanedione107222 | | Glyoxal, 1,2-ethanedione | -- | 0.1(s), (u)
• Graphite (natural)NIOSH REL TWA 2.5 mg/m3 (resp)
• Graphite (synthetic)NIOSH REL See Appendix D
• GypsumGypsum | 13397-24-5 | - | - | - |
• HafniumHafnium | 7440-58-6 | - | 0.5 | - |
• Halothane151677 | | Halothane | 2 | 16
• HDI; see Hexamethylene diisocyanate822060 | | HDI; see Hexamethylene diisocyanate
• Helium7440597 | | Helium | (h) | --
• HeptachlorHeptachlor | 76-44-8 | - | 0.5 | X |
• Heptane (n-Heptane)Heptane (n-Heptane) | 142-82-5 | 500 | 2000 | - |
• Hexachlorobenzene118741 | S | Hexachlorobenzene | -- | 0.002
• Hexachlorobutadiene87683 | S | Hexachlorobutadiene | 0.02 | 0.24
• Hexachlorocyclopentadiene77474 | | Hexachlorocyclopentadiene | 0.01 | 0.11
• HexachloroethaneHexachloroethane | 67-72-1 | 1 | 10 | X |
• Hexachloroethane; perchloroethane67721 | S | Hexachloroethane; perchloroethane | 1 | 10
• HexachloronaphthaleneHexachloronaphthalene | 1335-87-1 | - | 0.2 | X |
• HexafluoroacetoneNIOSH REL TWA 0.1 ppm (0.7 mg/m³) [skin]
• Hexamethyl phosphoramideNIOSH REL Ca See Appendix A
• Hexamethylene diisocyanateNIOSH REL TWA 0.005 ppm (0.035 mg/m3) C 0.020 ppm (0.140 mg/m3) [10-minute]
• Hexamethylene diisocyanate; HDI822060 | | Hexamethylene diisocyanate; HDI | 0.005 | 0.034
• HexoneNIOSH REL TWA 50 ppm (205 mg/m3) ST 75 ppm (300 mg/m3)
• Hexone (Methyl isobutyl ketone)Hexone (Methyl isobutyl ketone) | 108-10-1 | 100 | 410 | - |
• Hexone; see Methyl isobutyl ketone108101 | | Hexone; see Methyl isobutyl ketone
• Hexylene glycol107415 | | Hexylene glycol | 25 | 125 | C
• HydrazineHydrazine | 302-01-2 | 1 | 1.3 | X |
• Hydrobromic acid; see Hydrogen bromide10035106 | | Hydrobromic acid; see Hydrogen bromide
• Hydrochloric acid; see Hydrogen chloride7647010 | | Hydrochloric acid; see Hydrogen chloride
• Hydrocyanic acid; see Hydrogen cyanide74908 | | Hydrocyanic acid; see Hydrogen cyanide
• Hydrofluoric acid; see Hydrogen fluoride7664393 | | Hydrofluoric acid; see Hydrogen fluoride
• Hydrogen1333740 | | Hydrogen | (h) | --
• Hydrogen bromideHydrogen bromide | 10035-10-6 | 3 | 10 | - |
• Hydrogen chlorideHydrogen chloride | 7647-01-0 | (C)5 | (C)7 | - |
• Hydrogen cyanideHydrogen cyanide | 74-90-8 | 10 | 11 | X |
• Hydrogen fluorideNIOSH REL TWA 3 ppm (2.5 mg/m3) C 6 ppm (5 mg/m3) [15-minute]
• Hydrogen fluoride (as F)Hydrogen fluoride (as F) | 7664-39-3 | - | (2) | - |
• Hydrogen fluoride, as F7664393 | S | Hydrogen fluoride, as F | 0.4 | 0.33 | | 1 | 0.83
• Hydrogen peroxideHydrogen peroxide | 7722-84-1 | 1 | 1.4 | - |
• Hydrogen selenideNIOSH REL TWA 0.05 ppm (0.2 mg/m3)
• Hydrogen sulfideHydrogen sulfide | 7783-06-4 | - | (2) | - |
• Hydrogenated terphenyls61788327 | | Hydrogenated terphenyls | 0.5 | 5
• HydroquinoneHydroquinone | 123-31-9 | - | 2 | - |
• Hydroquinone; 1,4-benezendiol123319 | | Hydroquinone; 1,4-benezendiol | -- | 2
• Indene95136 | | Indene | 10 | 48
• Indium7440746 | | Indium | -- | 0.1
• IodineIodine | 7553-56-2 | (C)0.1 | (C)1 | - |
• Iodoform75478 | | Iodoform | 0.6 | 10
• IPDI; see Isophorone diisocyanate4098719 | | IPDI; see Isophorone diisocyanate
• Iron oxide dust and fume (as Fe)NIOSH REL TWA 5 mg/m3
• Iron oxide fumeIron oxide fume | 1309-37-1 | - | 10 | - |
• Iron pentacarbonyl, as Fe13463406 | | Iron pentacarbonyl, as Fe | 0.1 | 0.8 | | 0.2 | 1.6
• Isoamyl acetateIsoamyl acetate | 123-92-2 | 100 | 525 | - |
• Isoamyl alcohol; 3-methylbutanol123513 | | Isoamyl alcohol; 3-methylbutanol | 100 | 360 | | 125 | 450
• Isoamyl alcohol (secondary)NIOSH REL TWA 100 ppm (360 mg/m3) ST 125 ppm (450 mg/m3)
• IsobutaneNIOSH REL TWA 800 ppm (1900 mg/m3)
• Isobutyl acetateIsobutyl acetate | 110-19-0 | 150 | 700 | - |
• Isobutyl alcoholIsobutyl alcohol | 78-83-1 | 100 | 300 | - |
• IsobutyronitrileNIOSH REL TWA 8 ppm (22 mg/m3)
• Isoflurane26675467 | | Isoflurane | 2 | 15
• Isooctyl alcohol26952216 | S | Isooctyl alcohol | 50 | 270
• IsophoroneIsophorone | 78-59-1 | 25 | 140 | - |
• Isophorone diisocyanateNIOSH REL TWA 0.005 ppm (0.045 mg/m3) ST 0.02 ppm (0.180 mg/m3) [skin]
• Isophorone diisocyanate; IPDI4098719 | S | Isophorone diisocyanate; IPDI | 0.005 | 0.045 | | 0.02 | --
• Isopropyl acetateIsopropyl acetate | 108-21-4 | 250 | 950 | - |
• Isopropyl alcoholIsopropyl alcohol | 67-63-0 | 400 | 980 | - |
• Isopropyl etherIsopropyl ether | 108-20-3 | 500 | 2100 | - |
• Isopropyl ether; diisopropyl ether108203 | | Isopropyl ether; diisopropyl ether | 250 | 1,050
• Isopropyl glycidyl etherNIOSH REL C 50 ppm (240 mg/m3) [15-minute]
• IsopropylamineIsopropylamine | 75-31-0 | 5 | 12 | - |
• KaolinKaolin | 1332-58-7 | - | - | - |
• KeponeNIOSH REL Ca TWA 0.001 mg/m3
• KeroseneNIOSH REL TWA 100 mg/m3
• KeteneKetene | 463-51-4 | 0.5 | 0.9 | - |
• L.P.G.NIOSH REL TWA 1000 ppm (1800 mg/m3)
• LeadNIOSH REL TWA (8-hour) 0.050 mg/m3 See Appendix C
• Lead chromate, as Pb7758976 | | Lead chromate, as Pb | -- | 0.01
• Lead tetraethyl, see Tetraethyl lead78002 | | Lead tetraethyl, see Tetraethyl lead
• Lead tetramethyl, see Tetramethyl lead75741 | | Lead tetramethyl, see Tetramethyl lead
• LimestoneLimestone | 1317-65-3 | - | - | - |
• Limestone; calcium carbonate; see Particulates not otherwise regulated1317653 | | Limestone; calcium carbonate; see Particulates not otherwise regulated
• LindaneLindane | 58-89-9 | - | 0.5 | X |
• Lithium hydrideLithium hydride | 7580-67-8 | - | 0.025 | - |
• Lithium stearate4485125 | | Lithium stearate | -- | 10
• m-CresolNIOSH REL TWA 2.3 ppm (10 mg/m3)
• m-DinitrobenzeneNIOSH REL TWA 1 mg/m3 [skin]
• m-isomerm-isomer | 99-08-1 | - | - | - |
• m-Phthalodinitrile626175 | | m-Phthalodinitrile | -- | 5
• m-TerphenylNIOSH REL C 5 mg/m3 (0.5 ppm)
• m-Toluidine108441 | S | m-Toluidine | 2 | 9
• m-XyleneNIOSH REL TWA 100 ppm (435 mg/m3) ST 150 ppm (655 mg/m3)
• m-Xylene-a,a′-diamine1477550 | S | m-Xylene-a,a′-diamine | -- | 0.1 | C
• MagnesiteMagnesite | 546-93-0 | - | - | - |
• Magnesite; magnesium carbonate; see Particulates not otherwise regulated13717005 | | Magnesite; magnesium carbonate; see Particulates not otherwise regulated
• Magnesium oxide fumeMagnesium oxide fume | 1309-48-4 | - | - | - |
• Magnesium stearate557040 | | Magnesium stearate | -- | 10
• MalathionMalathion | 121-75-5 | - | - | - |
• Maleic anhydrideMaleic anhydride | 108-31-6 | 0.25 | 1 | - |
• MalonaldehydeNIOSH REL Ca See Appendix A See Appendix C (Aldehydes)
• MalononitrileNIOSH REL TWA 3 ppm (8 mg/m3)
• Manganese compounds and fume (as Mn)NIOSH REL TWA 1 mg/m3 ST 3 mg/m3
• Manganese compounds (as Mn)Manganese compounds (as Mn) | 7439-96-5 | - | (C)5 | - |
• Manganese, cyclopentadienyl-tricarbonyl, as Mn12079651 | S | Manganese, cyclopentadienyl-tricarbonyl, as Mn | -- | 0.1
• Manganese fume (as Mn)Manganese fume (as Mn) | 7439-96-5 | - | (C)5 | - |
• Manganese fume, as Mn7439965 | | Manganese fume, as Mn | -- | 0.2 | | -- | 3
• Manganese tetroxide (as Mn)NIOSH REL See Appendix D
• MarbleMarble | 1317-65-3 | - | - | - |
• MDA; see 4,4′-Methylene dianiline101779 | S | MDA; see 4,4′-Methylene dianiline
• MDI; see Methylene bis(phenylisocyanate)101688 | | MDI; see Methylene bis(phenylisocyanate)
• Mercury alkyls, as Hg7439976 | S | Mercury alkyls, as Hg | -- | 0.01 | 0.04 mg/M3 | -- | 0.03
• Mercury (aryl and inorganic) (as Hg)Mercury (aryl and inorganic) (as Hg) | 7439-97-6 | - | (2) | - |
• Mercury aryl compounds as Hg7439976 | S | Mercury aryl compounds as Hg | | 0.1 | C
• Mercury compounds [except (organo) alkyls] (as Hg)NIOSH REL NIOSH REL: Hg Vapor: TWA 0.05 mg/m3 [skin] Other: C 0.1 mg/m3 [skin]
• Mercury, metallic and inorganic compounds as Hg7439976 | S | Mercury, metallic and inorganic compounds as Hg | -- | 0.025 | 0.1 mg/M3
• Mercury (organo) alkyl compounds (as Hg)Mercury (organo) alkyl compounds (as Hg) | 7439-97-6 | - | (2) | - |
• Mercury (vapor) (as Hg)Mercury (vapor) (as Hg) | 7439-97-6 | - | (2) | - |
• Mesityl oxideMesityl oxide | 141-79-7 | 25 | 100 | - |
• Methacrylic acid79414 | S | Methacrylic acid | 20 | 70
• Methane74828 | | Methane | (h) | --
• Methanethiol; see Methyl mercaptan74931 | | Methanethiol; see Methyl mercaptan
• Methanol; see Methyl alcohol67561 | | Methanol; see Methyl alcohol
• Methomyl16752775 | S | Methomyl | -- | 2.5
• MethoxychlorMethoxychlor | 72-43-5 | - | - | - |
• Methoxyflurane76380 | | Methoxyflurane | 2 | 13
• Methyl 2-cyanoacrylate137053 | | Methyl 2-cyanoacrylate | 0.2 | 0.908
• Methyl acetateMethyl acetate | 79-20-9 | 200 | 610 | - |
• Methyl acetyleneNIOSH REL TWA 1000 ppm (1650 mg/m3)
• Methyl acetylene-propadiene mixtureNIOSH REL TWA 1000 ppm (1800 mg/m3) ST 1250 ppm (2250 mg/m3)
• Methyl acetylene (Propyne)Methyl acetylene (Propyne) | 74-99-7 | 1000 | 1650 | - |
• Methyl acetylene; propyne74997 | | Methyl acetylene; propyne | 1,000 | 1,650
• Methyl acrylateMethyl acrylate | 96-33-3 | 10 | 35 | X |
• Methyl alcoholMethyl alcohol | 67-56-1 | 200 | 260 | - |
• Methyl alcohol; methanol67561 | S | Methyl alcohol; methanol | 200 | 260 | 1000 ppm | 250 | 325
• Methyl amyl alcohol; see Methyl isobutyl carbinol108112 | | Methyl amyl alcohol; see Methyl isobutyl carbinol
• Methyl bromideMethyl bromide | 74-83-9 | (C)20 | (C)80 | X |
• Methyl Cellosolve®NIOSH REL TWA 0.1 ppm (0.3 mg/m3) [skin]
• Methyl Cellosolve® acetateNIOSH REL TWA 0.1 ppm (0.5 mg/m3) [skin]
• Methyl chlorideMethyl chloride | 74-87-3 | - | (2) | - |
• Methyl chloroformNIOSH REL C 350 ppm (1900 mg/m3) [15-minute]
• Methyl chloroform (1,1,1-Trichloroethane)Methyl chloroform (1,1,1-Trichloroethane) | 71-55-6 | 350 | 1900 | - |
• Methyl chloroform; 1,1,1-trichloroethane71556 | | Methyl chloroform; 1,1,1-trichloroethane | 350 | 1900 | 800 ppm | 450 | 2450
• Methyl chloromethyl ether; see Section 5209107302 | | Methyl chloromethyl ether; see Section 5209
• Methyl cyanide; see Acetonitrile75058 | | Methyl cyanide; see Acetonitrile
• Methyl demetonNIOSH REL TWA 0.5 mg/m3 [skin]
• Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone78933 | | Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone | 200 | 590 | | 300 | 885
• Methyl ethyl ketone peroxide1338234 | | Methyl ethyl ketone peroxide | 0.2 | 1.5 | C
• Methyl formateMethyl formate | 107-31-3 | 100 | 250 | - |
• Methyl hydrazineNIOSH REL Ca C 0.04 ppm (0.08 mg/m3) [2-hr]
• Methyl hydrazine (Monomethyl hydrazine)Methyl hydrazine (Monomethyl hydrazine) | 60-34-4 | (C)0.2 | (C)0.35 | X |
• Methyl hydrazine; monomethyl hydrazine60344 | S | Methyl hydrazine; monomethyl hydrazine | 0.01 | 0.019
• Methyl iodideMethyl iodide | 74-88-4 | 5 | 28 | X |
• Methyl isoamyl ketoneMethyl isoamyl ketone | 110-12-3 | 100 | 475 | - |
• Methyl isobutyl carbinolMethyl isobutyl carbinol | 108-11-2 | 25 | 100 | X |
• Methyl isobutyl carbinol; 4-methyl-2-pentanol; methyl amyl alcohol108112 | S | Methyl isobutyl carbinol; 4-methyl-2-pentanol; methyl amyl alcohol | 25 | 100 | | 40 | 165
• Methyl isobutyl ketone; Hexone108101 | | Methyl isobutyl ketone; Hexone | 50 | 205 | | 75 | 300
• Methyl isocyanateMethyl isocyanate | 624-83-9 | 0.02 | 0.05 | X |
• Methyl isopropyl ketone563804 | | Methyl isopropyl ketone | 200 | 705
• Methyl mercaptanMethyl mercaptan | 74-93-1 | (C)10 | (C)20 | - |
• Methyl methacrylateMethyl methacrylate | 80-62-6 | 100 | 410 | - |
• Methyl n-amyl ketoneMethyl n-amyl ketone | 110-43-0 | 100 | 465 | - |
• Methyl n-butyl ketone; 2-hexanone591786 | S | Methyl n-butyl ketone; 2-hexanone | 1 | 4 | | 10 | 40
• Methyl parathionNIOSH REL TWA 0.2 mg/m3 [skin]
• Methyl propyl ketone; 2-pentanone107879 | | Methyl propyl ketone; 2-pentanone | 200 | 700 | | 250 | 875
• Methyl silicateNIOSH REL TWA 1 ppm (6 mg/m3)
• Methyl sulfate; see Dimethyl sulfate77781 | | Methyl sulfate; see Dimethyl sulfate
• Methyl tert-butyl ether; MTBE1634044 | | Methyl tert-butyl ether; MTBE | 40 | 144
• Methyl vinyl ketone78944 | S | Methyl vinyl ketone | 0.05 | 0.14 | C
• MethylalNIOSH REL TWA 1000 ppm (3100 mg/m3)
• Methylal (Dimethoxy-methane)Methylal (Dimethoxy-methane) | 109-87-5 | 1000 | 3100 | - |
• Methylal; dimethoxymethane109875 | | Methylal; dimethoxymethane | 1,000 | 3,100
• MethylamineMethylamine | 74-89-5 | 10 | 12 | - |
• MethylcyclohexaneMethylcyclohexane | 108-87-2 | 500 | 2000 | - |
• MethylcyclohexanolMethylcyclohexanol | 25639-42-3 | 100 | 470 | - |
• Methylene bis(4-cyclohexylisocyanate)NIOSH REL C 0.01 ppm (0.11 mg/m3)
• Methylene bis(4-cyclohexylisocyanate); hydrogenated MDI5124301 | | Methylene bis(4-cyclohexylisocyanate); hydrogenated MDI | 0.005 | 0.054
• Methylene bis(phenylisocyanate); MDI; diphenylmethane diisocyanate101688 | | Methylene bis(phenylisocyanate); MDI; diphenylmethane diisocyanate | 0.005 | 0.051
• Methylene bisphenyl isocyanateNIOSH REL TWA 0.05 mg/m3 (0.005 ppm) C 0.2 mg/m3 (0.020 ppm) [10-minute]
• Methylene bisphenyl isocyanate (MDI)Methylene bisphenyl isocyanate (MDI) | 101-68-8 | (C)0.02 | (C)0.2 | - |
• Methylene chlorideMethylene chloride | 75-09-2 | - | (2) | - |
• Methylene chloride; dichloromethane (see also section 5202)75092 | | Methylene chloride; dichloromethane (see also section 5202) | 25 | 87 | | 125 | 435
• Metribuzin21087649 | | Metribuzin | -- | 5
• Mevinphos; 2-carbomethoxyl-1-propen-2-yl dimethyl phosphate7786347 | S | Mevinphos; 2-carbomethoxyl-1-propen-2-yl dimethyl phosphate | 0.01 | 0.1 | | 0.03 | 0.3
• Mica (containing less than 1% quartz)NIOSH REL TWA 3 mg/m3 (resp)
• MolybdenumNIOSH REL See Appendix D
• Monocrotophos6923224 | | Monocrotophos | -- | 0.25
• Monomethyl anilineMonomethyl aniline | 100-61-8 | 2 | 9 | X |
• Monomethylaniline; see N-Methylaniline100618 | | Monomethylaniline; see N-Methylaniline
• Monomethylhydrazine; see Methyl hydrazine60344 | | Monomethylhydrazine; see Methyl hydrazine
• MorpholineMorpholine | 110-91-8 | 20 | 70 | X |
• Muriatic acid; see Hydrogen chloride7647010 | | Muriatic acid; see Hydrogen chloride
• n-Amyl acetaten-Amyl acetate | 628-63-7 | 100 | 525 | - |
• n-Butyl-acetaten-Butyl-acetate | 123-86-4 | 150 | 710 | - |
• n-Butyl alcoholn-Butyl alcohol | 71-36-3 | 100 | 300 | - |
• n-Butyl alcohol; 1-butanol71363 | S | n-Butyl alcohol; 1-butanol | 50 | 150 | C
• n-Butyl glycidyl etherNIOSH REL C 5.6 ppm (30 mg/m3) [15-minute]
• n-Butyl lactate138227 | | n-Butyl lactate | 5 | 25
• n-Butyl mercaptan109795 | | n-Butyl mercaptan | 0.5 | 1.5
• n-ButyronitrileNIOSH REL TWA 8 ppm (22 mg/m3)
• N-EthylmorpholineN-Ethylmorpholine | 100-74-3 | 20 | 94 | X |
• n-Hexanen-Hexane | 110-54-3 | 500 | 1800 | - |
• n-HexanethiolNIOSH REL C 0.5 ppm (2.7 mg/m3) [15-minute]
• N-isopropylaniline768525 | S | N-isopropylaniline | 2 | 10
• N-Methylaniline; monomethylaniline100618 | S | N-Methylaniline; monomethylaniline | 0.5 | 2
• N-Methylpyrrolidone (NMP)872504 | S | N-Methylpyrrolidone (NMP) | 1 | 4
• N,N-Dimethylnitrosamine; see N-Nitrosodimethylamine, Section 520962759 | | N,N-Dimethylnitrosamine; see N-Nitrosodimethylamine, Section 5209
• N-NitrosodimethylamineNIOSH REL Ca See Appendix A
• N-Nitrosodimethylamine, see Section 520962759 | | N-Nitrosodimethylamine, see Section 5209
• n-PentaneNIOSH REL TWA 120 ppm (350 mg/m3) C 610 ppm (1800 mg/m3) [15-minute]
• N-Phenyl-β-naphthylamineNIOSH REL Ca* See Appendix A
• n-Propyl acetaten-Propyl acetate | 109-60-4 | 200 | 840 | - |
• n-Propyl alcoholn-Propyl alcohol | 71-23-8 | 200 | 500 | - |
• n-Propyl nitraten-Propyl nitrate | 627-13-4 | 25 | 110 | - |
• n-ValeraldehydeNIOSH REL TWA 50 ppm (175 mg/m3)
• Naled; o,o-dimethyl o-(1,2-dibromo-2,2-dichloroethyl) phosphate300765 | S | Naled; o,o-dimethyl o-(1,2-dibromo-2,2-dichloroethyl) phosphate | -- | 3
• Naphtha (Coal tar)Naphtha (Coal tar) | 8030-30-6 | 100 | 400 | - |
• Naphtha, coal tar8030317 | | Naphtha, coal tar | 100 | 400
• NaphthaleneNaphthalene | 91-20-3 | 10 | 50 | - |
• Naphthalene diisocyanateNIOSH REL TWA 0.040 mg/m3 (0.005 ppm) C 0.170 mg/m3 (0.020 ppm) [10-minute]
• Naphthalene diisocyanate; NDI25551284 | | Naphthalene diisocyanate; NDI | 0.01 | 0.085 | C
• Neon7440019 | | Neon | (h)
• Niax® Catalyst ESNNIOSH REL See Appendix C
• Nickel carbonylNIOSH REL Ca TWA 0.001 ppm (0.007 mg/m3)
• Nickel, metal and insoluble compounds (as Ni)Nickel, metal and insoluble compounds (as Ni) | 7440-02-0 | - | 1 | - |
• Nickel metal and other compounds (as Ni)NIOSH REL Ca TWA 0.015 mg/m3
• Nickel metal, as Ni7440020 | | Nickel metal, as Ni | -- | 0.5
• Nickel, soluble compounds (as Ni)Nickel, soluble compounds (as Ni) | 7440-02-0 | - | 1 | - |
• Nickel subsulfide12035722 | | Nickel subsulfide | -- | .05
• NicotineNicotine | 54-11-5 | - | 0.5 | X |
• Nitrapyrin1929824 | | Nitrapyrin | --
• Nitric acidNitric acid | 7697-37-2 | 2 | 5 | - |
• Nitric oxideNitric oxide | 10102-43-9 | 25 | 30 | - |
• NitrobenzeneNitrobenzene | 98-95-3 | 1 | 5 | X |
• NitroethaneNitroethane | 79-24-3 | 100 | 310 | - |
• Nitrogen7727379 | | Nitrogen | (h) | --
• Nitrogen dioxideNitrogen dioxide | 10102-44-0 | (C)5 | (C)9 | - |
• Nitrogen trifluorideNitrogen trifluoride | 7783-54-2 | 10 | 29 | - |
• NitroglycerinNitroglycerin | 55-63-0 | (C)0.2 | (C)2 | X |
• NitromethaneNitromethane | 75-52-5 | 100 | 250 | - |
• Nitrotrichloromethane; see Chloropicrin76062 | | Nitrotrichloromethane; see Chloropicrin
• Nitrous oxide0024972 | | Nitrous oxide | 50 | 90
• Nitrous oxideNIOSH REL TWA 25 ppm (46 mg/m3) (TWA over the time exposed)
• Nonane111842 | | Nonane | 200 | 1,050
• o-AnisidineNIOSH REL Ca TWA 0.5 mg/m3 [skin]
• o-Chlorobenzylidene malononitrileo-Chlorobenzylidene malononitrile | 2698-41-1 | 0.05 | 0.4 | - |
• o-Chlorostyrene2039874 | | o-Chlorostyrene | 50 | 285 | | 75 | 428
• o-Chlorotoluene95498 | S | o-Chlorotoluene | 50 | 250
• o-CresolNIOSH REL TWA 2.3 ppm (10 mg/m3)
• o-DianisidineNIOSH REL Ca See Appendix A See Appendix C
• o-Dichlorobenzeneo-Dichlorobenzene | 95-50-1 | (C)50 | (C)300 | - |
• o-DinitrobenzeneNIOSH REL TWA 1 mg/m3 [skin]
• o-isomero-isomer | 88-72-2 | - | - | - |
• o-Methylaniline; see o-Toluidine95534 | | o-Methylaniline; see o-Toluidine
• o-Methylcyclohexanoneo-Methylcyclohexanone | 583-60-8 | 100 | 460 | X |
• o,o-Dimethyl o-(1,2-dibromo-2,2-dichloroethyl) phosphate; see Naled300765 | | o,o-Dimethyl o-(1,2-dibromo-2,2-dichloroethyl) phosphate; see Naled
• o-sec-Butylphenol89725 | S | o-sec-Butylphenol | 5 | 30
• o-TerphenylNIOSH REL C 5 mg/m3 (0.5 ppm)
• o-TolidineNIOSH REL Ca C 0.02 mg/m3 [60-minute] [skin]
• o-Toluidineo-Toluidine | 95-53-4 | 5 | 22 | X |
• o-Toluidine; o-methylaniline95534 | S | o-Toluidine; o-methylaniline | 2 | 9
• o-XyleneNIOSH REL TWA 100 ppm (435 mg/m3) ST 150 ppm (655 mg/m3)
• OctachloronaphthaleneOctachloronaphthalene | 2234-13-1 | - | 0.1 | X |
• OctaneOctane | 111-65-9 | 500 | 2350 | - |
• Oil (mineral) mist, particulate8012951 | | Oil (mineral) mist, particulate | -- | (5)(l)
• Osmium tetroxideNIOSH REL TWA 0.002 mg/m3 (0.0002 ppm) ST 0.006 mg/m3 (0.0006 ppm)
• Oxalic acidOxalic acid | 144-62-7 | - | 1 | - |
• Oxygen difluorideOxygen difluoride | 7783-41-7 | 0.05 | 0.1 | - |
• OzoneOzone | 10028-15-6 | 0.1 | 0.2 | - |
• p-AnisidineNIOSH REL TWA 0.5 mg/m3 [skin]
• p-CresolNIOSH REL TWA 2.3 ppm (10 mg/m3)
• p-Dichlorobenzenep-Dichlorobenzene | 106-46-7 | 75 | 450 | - |
• p-Dihydroxybenzene; see Hydroquinone123319 | | p-Dihydroxybenzene; see Hydroquinone
• p-DinitrobenzeneNIOSH REL TWA 1 mg/m3 [skin]
• p-Dioxane;123911 | S | p-Dioxane;
• p-isomerp-isomer | 99-99-0 | - | - | - |
• p-Nitroanilinep-Nitroaniline | 100-01-6 | 1 | 6 | X |
• p-Nitrochlorobenzenep-Nitrochlorobenzene | 100-00-5 | - | 1 | X |
• p-Nitrochlorobenzene; 1-chloro-4-nitrobenzene100005 | S | p-Nitrochlorobenzene; 1-chloro-4-nitrobenzene | 0.1 | 0.64
• p-Phenylene diaminep-Phenylene diamine | 106-50-3 | - | 0.1 | X |
• p-TerphenylNIOSH REL C 5 mg/m3 (0.5 ppm)
• p-tert-Butyltoluenep-tert-Butyltoluene | 98-51-1 | 10 | 60 | - |
• p-Toluidine106490 | S | p-Toluidine | 2 | 9
• p-XyleneNIOSH REL TWA 100 ppm (435 mg/m3) ST 150 ppm (655 mg/m3)
• Paraffin wax fume8002742 | | Paraffin wax fume | -- | 2
• Paraquat (Paraquat dichloride)NIOSH REL TWA 0.1 mg/m3 (resp) [skin]
• ParathionParathion | 56-38-2 | - | 0.1 | X |
• PCP; see Pentachlorophenol87865 | S | PCP; see Pentachlorophenol
• PentaboranePentaborane | 19624-22-7 | 0.005 | 0.01 | - |
• PentachloroethaneNIOSH REL Handle with care in the workplace. See Appendix C (Chloroethanes)
• PentachloronaphthalenePentachloronaphthalene | 1321-64-8 | - | 0.5 | X |
• PentachlorophenolPentachlorophenol | 87-86-5 | - | 0.5 | X |
• Pentachlorophenol; PCP87865 | S | Pentachlorophenol; PCP | -- | 0.5
• PentaerythritolPentaerythritol | 115-77-5 | - | - | - |
• Pentaerythritol; tetrakis-(hydroxymethyl)methane; tetra-methylolmethane; see Particulates not otherwise regulated115775 | | Pentaerythritol; tetrakis-(hydroxymethyl)methane; tetra-methylolmethane; see Particulates not otherwise regulated
• Perchloroethane; see Hexachloroethane67721 | | Perchloroethane; see Hexachloroethane
• Perchloroethylene127184 | | Perchloroethylene | 25 | 170 | 300 ppm | 100 | 685
• Perchloroethylene (Tetrachloroethylene)Perchloroethylene (Tetrachloroethylene) | 127-18-4 | - | (2) | - |
• Perchloromethyl mercaptanPerchloromethyl mercaptan | 594-42-3 | 0.1 | 0.8 | - |
• Perchloromethyl mercaptan; trichloromethanethiol594423 | | Perchloromethyl mercaptan; trichloromethanethiol | 0.1 | 0.8
• Perchloryl fluoridePerchloryl fluoride | 7616-94-6 | 3 | 13.5 | - |
• Perfluoroisobutylene382218 | | Perfluoroisobutylene | 0.01 | 0.082 | C
• PerliteNIOSH REL TWA 10 mg/m3 (total) TWA 5 mg/m3 (resp)
• Petroleum distillates (naphtha)NIOSH REL TWA 350 mg/m3 C 1800 mg/m3 [15-minute]
• PhenolPhenol | 108-95-2 | 5 | 19 | X |

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