# Acetic anhydride — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

For Acetic anhydride, cas no. is 108-24-7; pel (ppm) is 5; pel (mg/m³) is 20, verified against its source on 2026-08-05.

- **Substance:** Acetic anhydride
- **CAS No.:** 108-24-7
- **PEL (ppm):** 5
- **PEL (mg/m³):** 20

## What the source says

> Acetic anhydride | 108-24-7 | 5 | 20 | - |

## 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.

### Substance

osha.gov says substance is **Acetic anhydride**, as of 2026-08-05.

> Acetic anhydride | 108-24-7 | 5 | 20 | - |

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

dir.ca.gov says substance is **Acetic Anhydride**, as of 2026-08-05.

> 108247 | | Acetic Anhydride | 5 | 20 | C

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


## Source

- https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
- https://www.dir.ca.gov/title8/5155.html

Last verified: 2026-08-05. Review by: 2027-08-05.
Part of [US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side](https://referencesource.org/workplace-exposure-limits/).