---
type: threshold
id: alpha-methylstyrene-1-methyl-1-phenylethene
asset: workplace-exposure-limits
title: "alpha-Methylstyrene; 1-methyl-1-phenylethene — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side"
sources:
  - https://www.dir.ca.gov/title8/5155.html
source_quote: "98839 | | alpha-Methylstyrene; 1-methyl-1-phenylethene | 50 | 240 | | 100 | 485"
generated: true
harvested: 2026-08-05
stale_after: 2027-08-05
substance: "alpha-Methylstyrene; 1-methyl-1-phenylethene"
pel_ppm: "50"
pel_mgm3: "240"
stel_ppm: "100"
stel_mgm3: "485"
verified: true
---
**Substance:** alpha-Methylstyrene; 1-methyl-1-phenylethene

**PEL (ppm):** 50

**PEL (mg/m³):** 240

**STEL (ppm):** 100

**STEL (mg/m³):** 485

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

Source: <https://www.dir.ca.gov/title8/5155.html>