alpha-Methyl styrene — workplace exposure limit
What is the pel (ppm) for alpha-Methyl styrene — workplace exposure limit?
For alpha-Methyl styrene, pel (ppm) is (C)100; pel (mg/m³) is (C)480; cas no. is 98-83-9, verified against its source on 2026-08-05.
alpha-Methyl styrene | 98-83-9 | (C)100 | (C)480 | - |
— osha.gov, retrieved 2026-08-05
- Substance
- alpha-Methyl styrene verified
- CAS No.
- 98-83-9 verified
- PEL (ppm)
- (C)100 verified
- PEL (mg/m³)
- (C)480 verified
- NIOSH REL (ppm)
- TWA 50 per cdc.gov
- NIOSH REL (mg/m³)
- 240 per cdc.gov
- STEL (ppm)
- 100 per dir.ca.gov
- STEL (mg/m³)
- 485 per dir.ca.gov
What cdc.gov says
NIOSH REL TWA 50 ppm (240 mg/m3) ST 100 ppm (485 mg/m3)
— 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 (C)100, as of 2026-08-05.
alpha-Methyl styrene | 98-83-9 | (C)100 | (C)480 | - |
https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
dir.ca.gov says pel (ppm) is 50, as of 2026-08-05.
98839 | | alpha-Methylstyrene; 1-methyl-1-phenylethene | 50 | 240 | | 100 | 485
https://www.dir.ca.gov/title8/5155.html
PEL (mg/m³)
osha.gov says pel (mg/m³) is (C)480, as of 2026-08-05.
alpha-Methyl styrene | 98-83-9 | (C)100 | (C)480 | - |
https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
dir.ca.gov says pel (mg/m³) is 240, as of 2026-08-05.
98839 | | alpha-Methylstyrene; 1-methyl-1-phenylethene | 50 | 240 | | 100 | 485
Sources
- osha.govhttps://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
- cdc.govhttps://www.cdc.gov/niosh/npg/npgd0429.html
- dir.ca.govhttps://www.dir.ca.gov/title8/5155.html