# Methyl acetylene (Propyne) — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

For Methyl acetylene (Propyne), cas no. is 74-99-7; pel (ppm) is 1000; pel (mg/m³) is 1650, verified against its source on 2026-08-05.

- **Substance:** Methyl acetylene (Propyne)
- **CAS No.:** 74-99-7
- **PEL (ppm):** 1000
- **PEL (mg/m³):** 1650

## What the source says

> Methyl acetylene (Propyne) | 74-99-7 | 1000 | 1650 | - |

## Source

- https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1

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/).