---
type: threshold
id: o-chlorostyrene
asset: workplace-exposure-limits
title: "o-Chlorostyrene — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side"
sources:
  - https://www.dir.ca.gov/title8/5155.html
source_quote: "2039874 | | o-Chlorostyrene | 50 | 285 | | 75 | 428"
generated: true
harvested: 2026-08-05
stale_after: 2027-08-05
substance: "o-Chlorostyrene"
pel_ppm: "50"
pel_mgm3: "285"
stel_ppm: "75"
stel_mgm3: "428"
verified: true
---
**Substance:** o-Chlorostyrene

**PEL (ppm):** 50

**PEL (mg/m³):** 285

**STEL (ppm):** 75

**STEL (mg/m³):** 428

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

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