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

For Trimellitic anhydride, pel (ppm) is 0.005; pel (mg/m³) is 0.04; ceiling is C, verified against its source on 2026-08-05.

- **Substance:** Trimellitic anhydride
- **PEL (ppm):** 0.005
- **PEL (mg/m³):** 0.04
- **Ceiling:** C

## What the source says

> 552307 | | Trimellitic anhydride | 0.005 | 0.04 | C

## Source

- 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/).