# 1-Pentanethiol — workplace exposure limit

For 1-Pentanethiol, niosh rel (ppm) is C 0.5; niosh rel (mg/m³) is 2.1; cas no. is 110-66-7, verified against its source on 2026-09-08.

- **Substance:** 1-Pentanethiol _(verified: appears in its own passage below)_
- **CAS No.:** 110-66-7 _(verified: appears in its own passage below)_
- **NIOSH REL (ppm):** C 0.5 _(verified: appears in the quote below)_
- **NIOSH REL (mg/m³):** 2.1 _(verified: appears in the quote below)_

## What the source says

> NIOSH REL C 0.5 ppm (2.1 mg/m3) [15-minute]

## Where each value comes from

This source states these in separate places, so each value is shown with the passage that states it.

### Substance

> CDC - NIOSH Pocket Guide to Chemical Hazards - 1-Pentanethiol

### CAS No.

> CAS No. 110-66-7

## Source

- https://www.cdc.gov/niosh/npg/npgd0487.html

Last verified: 2026-09-08. Review by: 2027-09-08.
Part of [US workplace chemical exposure limits: federal OSHA, Cal/OSHA and NIOSH, side by side](https://referencesource.org/workplace-exposure-limits/).