Maleic anhydride — workplace exposure limit
What is the pel (ppm) for Maleic anhydride — workplace exposure limit?
For Maleic anhydride, pel (ppm) is 0.25; pel (mg/m³) is 1; cas no. is 108-31-6, verified against its source on 2026-08-05.
Maleic anhydride | 108-31-6 | 0.25 | 1 | - |
— osha.gov, retrieved 2026-08-05
- Substance
- Maleic anhydride verified
- CAS No.
- 108-31-6 verified
- PEL (ppm)
- 0.25 verified
- PEL (mg/m³)
- 1 verified
- NIOSH REL (ppm)
- 0.25 per cdc.gov
- NIOSH REL (mg/m³)
- TWA 1 per cdc.gov
What cdc.gov says
NIOSH REL TWA 1 mg/m3 (0.25 ppm)
— cdc.gov, retrieved 2026-09-08
Sources disagree
More than one authority states this, and they do not state the same thing. Both are reproduced with the source each came from — deciding between them is yours, not ours.
PEL (ppm)
osha.gov says pel (ppm) is 0.25, as of 2026-08-05.
Maleic anhydride | 108-31-6 | 0.25 | 1 | - |
https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
dir.ca.gov says pel (ppm) is 0.1, as of 2026-08-05.
108316 | | Maleic anhydride; cis-butenedioic anhydride | 0.1 | 0.4
https://www.dir.ca.gov/title8/5155.html
PEL (mg/m³)
osha.gov says pel (mg/m³) is 1, as of 2026-08-05.
Maleic anhydride | 108-31-6 | 0.25 | 1 | - |
https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
dir.ca.gov says pel (mg/m³) is 0.4, as of 2026-08-05.
108316 | | Maleic anhydride; cis-butenedioic anhydride | 0.1 | 0.4
Sources
- osha.govhttps://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
- cdc.govhttps://www.cdc.gov/niosh/npg/npgd0376.html
- dir.ca.govhttps://www.dir.ca.gov/title8/5155.html