Perchloromethyl mercaptan — CAS 594-42-3 — workplace exposure limit
What is the pel (ppm) for Perchloromethyl mercaptan — CAS 594-42-3 — workplace exposure limit?
For Perchloromethyl mercaptan, pel (ppm) is 0.1; pel (mg/m³) is 0.8; cas no. is 594-42-3, verified against its source on 2026-08-05.
Perchloromethyl mercaptan | 594-42-3 | 0.1 | 0.8 | - |
— osha.gov, retrieved 2026-08-05
0.1
The most of this substance workplace air may legally contain, averaged over an 8-hour shift — OSHA's permissible exposure limit (PEL), in parts per million, from the agency's own table row quoted below. Where federal OSHA and Cal/OSHA disagree, both limits are stated, each with its own agency's table row as evidence. NIOSH's number, where there is one, is shown separately: it is a recommended limit, not a legal one, and it is often the strictest of the three.
- Substance
- Perchloromethyl mercaptan verified
- CAS No.
- 594-42-3 verified
- PEL (ppm)
- 0.1 verified
- PEL (mg/m³)
- 0.8 verified
- NIOSH REL (ppm)
- TWA 0.1 per cdc.gov
- NIOSH REL (mg/m³)
- 0.8 per cdc.gov
What cdc.gov says
NIOSH REL TWA 0.1 ppm (0.8 mg/m3)
— cdc.gov, retrieved 2026-09-08
Substance
CDC - NIOSH Pocket Guide to Chemical Hazards - Perchloromethyl mercaptan
CAS No.
CAS No. 594-42-3
What dir.ca.gov says
594423 | | Perchloromethyl mercaptan; trichloromethanethiol | 0.1 | 0.8
— dir.ca.gov, retrieved 2026-08-05
What dir.ca.gov says
594423 | | Trichloromethanethiol; see Perchloromethyl mercaptan
— dir.ca.gov, retrieved 2026-08-05
Sources
- osha.govhttps://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
- cdc.govhttps://www.cdc.gov/niosh/npg/npgd0489.html
- dir.ca.govhttps://www.dir.ca.gov/title8/5155.html