Reference Source

Calcium oxide

For Calcium oxide, cas no. is 1305-78-8; pel (mg/m³) is 5, verified against its source on 2026-08-05.

Substance
Calcium oxide
CAS No.
1305-78-8
PEL (mg/m³)
5
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

Calcium oxide | 1305-78-8 | - | 5 | - |

— 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 (mg/m³)

osha.gov says pel (mg/m³) is 5, as of 2026-08-05.

Calcium oxide | 1305-78-8 | - | 5 | - |

https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1

dir.ca.gov says pel (mg/m³) is 2, as of 2026-08-05.

1305788 | | Calcium oxide | -- | 2

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.