Butyl mercaptan — CAS 109-79-5 — workplace exposure limit
What is the pel (ppm) for Butyl mercaptan — CAS 109-79-5 — workplace exposure limit?
For Butyl mercaptan, pel (ppm) is disputed: 10 per osha.gov, 0.5 per dir.ca.gov; pel (mg/m³) is disputed: 35 per osha.gov, 1.5 per dir.ca.gov; cas no. is 109-79-5, verified against its source on 2026-08-05.
Butyl mercaptan | 109-79-5 | 10 | 35 | - |
— osha.gov, retrieved 2026-08-05
- Substance
- Butyl mercaptan verified
- CAS No.
- 109-79-5 verified
- PEL (ppm)
- 10 sources disagree
- PEL (mg/m³)
- 35 sources disagree
- NIOSH REL (ppm)
- C 0.5 per cdc.gov
- NIOSH REL (mg/m³)
- 1.8 per cdc.gov
What cdc.gov says
NIOSH REL C 0.5 ppm (1.8 mg/m3) [15-minute]
— cdc.gov, retrieved 2026-09-08
Substance
CDC - NIOSH Pocket Guide to Chemical Hazards - n-Butyl mercaptan
CAS No.
CAS No. 109-79-5
What dir.ca.gov says
109795 | | 1-Butanethiol; see Butyl mercaptan
— dir.ca.gov, retrieved 2026-08-05
Sources disagree
More than one authority states this, and they do not state the same thing. Both are reproduced with the source each came from — deciding between them is yours, not ours.
PEL (ppm)
osha.gov says pel (ppm) is 10, as of 2026-08-05.
Butyl mercaptan | 109-79-5 | 10 | 35 | - |
https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
dir.ca.gov says pel (ppm) is 0.5, as of 2026-08-05.
109795 | | n-Butyl mercaptan | 0.5 | 1.5
https://www.dir.ca.gov/title8/5155.html
PEL (mg/m³)
osha.gov says pel (mg/m³) is 35, as of 2026-08-05.
Butyl mercaptan | 109-79-5 | 10 | 35 | - |
https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
dir.ca.gov says pel (mg/m³) is 1.5, as of 2026-08-05.
109795 | | n-Butyl mercaptan | 0.5 | 1.5
Sources
- osha.govhttps://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
- dir.ca.govhttps://www.dir.ca.gov/title8/5155.html
- cdc.govhttps://www.cdc.gov/niosh/npg/npgd0083.html