---
type: threshold
id: 1-2-4-trichlorobenzene
asset: workplace-exposure-limits
title: "1,2,4-Trichlorobenzene — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side"
sources:
  - https://www.dir.ca.gov/title8/5155.html
source_quote: "120821 | | 1,2,4-Trichlorobenzene | 5 | 40 | C"
generated: true
harvested: 2026-08-05
stale_after: 2027-08-05
substance: "1,2,4-Trichlorobenzene"
pel_ppm: "5"
pel_mgm3: "40"
ceiling: "C"
verified: true
---
**Substance:** 1,2,4-Trichlorobenzene

**PEL (ppm):** 5

**PEL (mg/m³):** 40

**Ceiling:** C

> 120821 | | 1,2,4-Trichlorobenzene | 5 | 40 | C

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