# Mesityl oxide — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

For Mesityl oxide, cas no. is 141-79-7; pel (ppm) is 25; pel (mg/m³) is 100, verified against its source on 2026-08-05.

- **Substance:** Mesityl oxide
- **CAS No.:** 141-79-7
- **PEL (ppm):** 25
- **PEL (mg/m³):** 100

## What the source says

> Mesityl oxide | 141-79-7 | 25 | 100 | - |

## 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/).