# alpha-Methylstyrene; 1-methyl-1-phenylethene — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

For alpha-Methylstyrene; 1-methyl-1-phenylethene, pel (ppm) is 50; pel (mg/m³) is 240; stel (ppm) is 100; stel (mg/m³) is 485, verified against its source on 2026-08-05.

- **Substance:** alpha-Methylstyrene; 1-methyl-1-phenylethene
- **PEL (ppm):** 50
- **PEL (mg/m³):** 240
- **STEL (ppm):** 100
- **STEL (mg/m³):** 485

## What the source says

> 98839 | | alpha-Methylstyrene; 1-methyl-1-phenylethene | 50 | 240 | | 100 | 485

## Source

- https://www.dir.ca.gov/title8/5155.html

Last verified: 2026-08-05. Review by: 2027-08-05.
Part of [US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side](https://referencesource.org/workplace-exposure-limits/).