---
type: threshold
id: styrene-monomer-phenylethylene
asset: workplace-exposure-limits
title: "Styrene (monomer); phenylethylene — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side"
sources:
  - https://www.dir.ca.gov/title8/5155.html
source_quote: "100425 | S | Styrene (monomer); phenylethylene | 50 | 215 | 500 ppm | 100 | 425"
generated: true
harvested: 2026-08-05
stale_after: 2027-08-05
substance: "Styrene (monomer); phenylethylene"
pel_ppm: "50"
pel_mgm3: "215"
ceiling: "500 ppm"
stel_ppm: "100"
stel_mgm3: "425"
verified: true
---
**Substance:** Styrene (monomer); phenylethylene

**PEL (ppm):** 50

**PEL (mg/m³):** 215

**Ceiling:** 500 ppm

**STEL (ppm):** 100

**STEL (mg/m³):** 425

> 100425 | S | Styrene (monomer); phenylethylene | 50 | 215 | 500 ppm | 100 | 425

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