# o-Chlorostyrene — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

For o-Chlorostyrene, pel (ppm) is 50; pel (mg/m³) is 285; stel (ppm) is 75; stel (mg/m³) is 428, verified against its source on 2026-08-05.

- **Substance:** o-Chlorostyrene
- **PEL (ppm):** 50
- **PEL (mg/m³):** 285
- **STEL (ppm):** 75
- **STEL (mg/m³):** 428

## What the source says

> 2039874 | | o-Chlorostyrene | 50 | 285 | | 75 | 428

## 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/).