# Methyl demeton — workplace exposure limit

For Methyl demeton, niosh rel (mg/m³) is TWA 0.5; cas no. is 8022-00-2, verified against its source on 2026-09-08.

- **Substance:** Methyl demeton _(verified: appears in its own passage below)_
- **CAS No.:** 8022-00-2 _(verified: appears in its own passage below)_
- **NIOSH REL (mg/m³):** TWA 0.5 _(verified: appears in the quote below)_
- **PEL (mg/m³):** 0.5 _(per dir.ca.gov, not stated by the source above)_

## What the source says

> NIOSH REL TWA 0.5 mg/m3 [skin]

## 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 - Methyl demeton

### CAS No.

> CAS No. 8022-00-2

## What dir.ca.gov says

> 8022002 | S | Methyl demeton; a mixture of o,o-dimethyl o-(2-(ethylthio)ethyl) phosphorothioate and o,o-dimethyl S-(2-(ethylthio)-ethyl) phosphorothioate | -- | 0.5

Source: https://www.dir.ca.gov/title8/5155.html

## Source

- https://www.cdc.gov/niosh/npg/npgd0410.html
- https://www.dir.ca.gov/title8/5155.html

Last verified: 2026-09-08. Review by: 2027-08-05.
Part of [US workplace chemical exposure limits: federal OSHA, Cal/OSHA and NIOSH, side by side](https://referencesource.org/workplace-exposure-limits/).