1,2,4-Trichlorobenzene — workplace exposure limit
What is the pel (ppm) for 1,2,4-Trichlorobenzene — workplace exposure limit?
For 1,2,4-Trichlorobenzene, pel (ppm) is 5; pel (mg/m³) is 40; ceiling is C; cas no. is 120821, verified against its source on 2026-08-05.
120821 | | 1,2,4-Trichlorobenzene | 5 | 40 | C
— dir.ca.gov, retrieved 2026-08-05
5
The most of this substance workplace air may legally contain, averaged over an 8-hour shift — OSHA's permissible exposure limit (PEL), in parts per million, from the agency's own table row quoted below. Where federal OSHA and Cal/OSHA disagree, both limits are stated, each with its own agency's table row as evidence. NIOSH's number, where there is one, is shown separately: it is a recommended limit, not a legal one, and it is often the strictest of the three.
- Substance
- 1,2,4-Trichlorobenzene verified
- CAS No.
- 120821 verified
- PEL (ppm)
- 5 verified
- PEL (mg/m³)
- 40 verified
- Ceiling
- C verified
- NIOSH REL (ppm)
- C 5 per cdc.gov
- NIOSH REL (mg/m³)
- 40 per cdc.gov
What cdc.gov says
NIOSH REL C 5 ppm (40 mg/m3)
— cdc.gov, retrieved 2026-09-08
Sources
- dir.ca.govhttps://www.dir.ca.gov/title8/5155.html
- cdc.govhttps://www.cdc.gov/niosh/npg/npgd0627.html