Carbon monoxide — CAS 630-08-0 — workplace exposure limit
What is the pel (ppm) for Carbon monoxide — CAS 630-08-0 — workplace exposure limit?
For Carbon monoxide, pel (ppm) is disputed: 50 per osha.gov, 25 per dir.ca.gov; pel (mg/m³) is disputed: 55 per osha.gov, 29 per dir.ca.gov; cas no. is 630-08-0, verified against its source on 2026-08-05.
Carbon monoxide | 630-08-0 | 50 | 55 | - |
— osha.gov, retrieved 2026-08-05
- Substance
- Carbon monoxide verified
- CAS No.
- 630-08-0 verified
- PEL (ppm)
- 50 sources disagree
- PEL (mg/m³)
- 55 sources disagree
- Ceiling
- 200 ppm per dir.ca.gov
- Ceiling notation
- a ceiling value in addition to the TWA values per dir.ca.gov
- NIOSH REL (ppm)
- TWA 35 per cdc.gov
- NIOSH REL (mg/m³)
- 40 per cdc.gov
What cdc.gov says
NIOSH REL TWA 35 ppm (40 mg/m3) C 200 ppm (229 mg/m3)
— cdc.gov, retrieved 2026-09-08
Substance
CDC - NIOSH Pocket Guide to Chemical Hazards - Carbon monoxide
CAS No.
CAS No. 630-08-0
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 50, as of 2026-08-05.
Carbon monoxide | 630-08-0 | 50 | 55 | - |
https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
dir.ca.gov says pel (ppm) is 25, as of 2026-09-28.
630080 | | Carbon monoxide | 25 | 29 | 200 ppm
https://www.dir.ca.gov/title8/5155.html
PEL (mg/m³)
osha.gov says pel (mg/m³) is 55, as of 2026-08-05.
Carbon monoxide | 630-08-0 | 50 | 55 | - |
https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
dir.ca.gov says pel (mg/m³) is 29, as of 2026-09-28.
630080 | | Carbon monoxide | 25 | 29 | 200 ppm
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/npgd0105.html