Trimellitic anhydride — workplace exposure limit
What is the pel (ppm) for Trimellitic anhydride — workplace exposure limit?
For Trimellitic anhydride, pel (ppm) is 0.005; pel (mg/m³) is 0.04; ceiling is C; cas no. is 552307, verified against its source on 2026-08-05.
552307 | | Trimellitic anhydride | 0.005 | 0.04 | C
— dir.ca.gov, retrieved 2026-08-05
0.005
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
- Trimellitic anhydride verified
- CAS No.
- 552307 verified
- PEL (ppm)
- 0.005 verified
- PEL (mg/m³)
- 0.04 verified
- Ceiling
- C verified
- NIOSH REL (ppm)
- TWA 0.005 per cdc.gov
- NIOSH REL (mg/m³)
- 0.04 per cdc.gov
What cdc.gov says
NIOSH REL TWA 0.005 ppm (0.04 mg/m3) Should be handled in the workplace as an extremely toxic substance
— cdc.gov, retrieved 2026-09-08
Sources
- dir.ca.govhttps://www.dir.ca.gov/title8/5155.html
- cdc.govhttps://www.cdc.gov/niosh/npg/npgd0635.html