# Methyl acetylene; propyne — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

For Methyl acetylene; propyne, pel (ppm) is 1,000; pel (mg/m³) is 1,650, verified against its source on 2026-08-05.

- **Substance:** Methyl acetylene; propyne
- **PEL (ppm):** 1,000
- **PEL (mg/m³):** 1,650

## What the source says

> 74997 | | Methyl acetylene; propyne | 1,000 | 1,650

## 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/).