# 1,2,4-Trichlorobenzene — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

For 1,2,4-Trichlorobenzene, pel (ppm) is 5; pel (mg/m³) is 40; ceiling is C, verified against its source on 2026-08-05.

- **Substance:** 1,2,4-Trichlorobenzene
- **PEL (ppm):** 5
- **PEL (mg/m³):** 40
- **Ceiling:** C

## What the source says

> 120821 | | 1,2,4-Trichlorobenzene | 5 | 40 | 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/).