# n-Butyl mercaptan — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

For n-Butyl mercaptan, pel (ppm) is 0.5; pel (mg/m³) is 1.5, verified against its source on 2026-08-05.

- **Substance:** n-Butyl mercaptan
- **PEL (ppm):** 0.5
- **PEL (mg/m³):** 1.5

## What the source says

> 109795 | | n-Butyl mercaptan | 0.5 | 1.5

## 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/).