Reference Source

Carbon monoxide

For Carbon monoxide, cas no. is 630-08-0; pel (ppm) is 50; pel (mg/m³) is 55, verified against its source on 2026-08-05.

Substance
Carbon monoxide
CAS No.
630-08-0
PEL (ppm)
50
PEL (mg/m³)
55
Sourceosha.gov
Verified2026-08-05
Review by2027-08-05
DatasetUS workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

What the source says

Carbon monoxide | 630-08-0 | 50 | 55 | - |

osha.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 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 2026-08-05.

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 2026-08-05.

630080 | | Carbon monoxide | 25 | 29 | 200 ppm

https://www.dir.ca.gov/title8/5155.html

Sources

Last verified against source: 2026-08-05. Scheduled for re-check by: 2027-08-05. This page as Markdown · OKF concept · full dataset as JSON.