---
title: "Methanethiol (74-93-1): exposure limits and sampling"
url: https://analyt-mtc.com/tools/hazard-search/methanethiol-74-93-1/
lang: en
alternates:
  en: https://analyt-mtc.com/tools/hazard-search/methanethiol-74-93-1/
  de: https://analyt-mtc.com/de/tools/gefahrstoffsuche/methanethiol-74-93-1/
---

Hazard search

# Methanethiol

CAS number

74-93-1

Also known as

Mercaptomethane · Methyl mercaptan · Thiomethanol

## UK workplace exposure limits

| Limit | Value | Applies to |
| --- | --- | --- |
| 8-hour TWA | 0.5 ppm |  |
| 8-hour TWA | 1 mg/m³ |  |

## Sampling methods

| Method | Sampling | Medium | Analysis | Part numbers |
| --- | --- | --- | --- | --- |
| **NIOSH 2542** / Mercaptans by GC-FPD / [Method document (opens in a new tab)](http://www.cdc.gov/niosh/docs/2003-154/pdfs/2542.pdf) | Active (pump) | Coated glass fibre filter in cassette | GC-FPD | [225-9007](https://analyt-mtc.com/catalog/product/skc-coated-treated-filters/#part-225-9007) / [225-1](https://analyt-mtc.com/catalog/product/aluminium-respirable-dust-cyclone/#part-225-1) |
| **OSHA 26** / Methyl mercaptan by GC-FPD / [Method document (opens in a new tab)](https://www.osha.gov/sites/default/files/methods/osha-26.pdf) | Active (pump) | Coated glass fibre filter in cassette | GC-FPD | [225-9007](https://analyt-mtc.com/catalog/product/skc-coated-treated-filters/#part-225-9007) / [225-1](https://analyt-mtc.com/catalog/product/aluminium-respirable-dust-cyclone/#part-225-1) |
| **Non-agency** / Methyl mercaptan by Colorimetric analysis | Direct-reading | Gastec Detector Tube |  | [810-71H](https://analyt-mtc.com/catalog/product/gastec-colour-gas-detector-tubes/#part-gst-71h) / [810-71](https://analyt-mtc.com/catalog/product/gastec-colour-gas-detector-tubes/#part-gst-71) / [810-70](https://analyt-mtc.com/catalog/product/gastec-colour-gas-detector-tubes/#part-gst-70) / [810-70L](https://analyt-mtc.com/catalog/product/gastec-colour-gas-detector-tubes/#part-gst-70l) / [810-70LN](https://analyt-mtc.com/catalog/product/gastec-colour-gas-detector-tubes/#part-gst-70ln) |
| **Non-agency 42** | Active (pump) |  | GC-FPD | [231-10](https://analyt-mtc.com/catalog/product/skc-tedlar-sample-bags/#part-231-10) |

Methods and limits as published by their agencies and summarised by SKC; check the current method and the limit that applies to you before sampling.

Source: [SKC Ltd (UK), Hazard Search, used with SKC's permission (opens in a new tab)](https://www.skcltd.com/hazard-search.html); [SKC Inc. (USA), Sampling Guides, used with SKC's permission (opens in a new tab)](https://international.skcinc.com/sampling-guides/)