# Methyl Mercaptan — OSHA PSM vs EPA RMP: chemical threshold quantities side by side

For Methyl Mercaptan, cas no. is 74-93-1; osha psm tq (lbs) is 5000, verified against its source on 2026-08-15.

- **Substance:** Methyl Mercaptan _(verified: appears in the quote below)_
- **CAS No.:** 74-93-1 _(verified: appears in the quote below)_
- **OSHA PSM TQ (lbs):** 5000 _(verified: appears in the quote below)_
- **EPA RMP TQ (lbs):** 10,000 _(per ecfr.gov, not stated by the source above)_
- **RMP category:** toxic _(per ecfr.gov, not stated by the source above)_
- **RMP basis for listing:** b _(per ecfr.gov, not stated by the source above)_

## What the source says

> Methyl Mercaptan | 74-93-1 | 5000

## What ecfr.gov says

> Methyl mercaptan [Methanethiol] | 74-93-1 | 10,000 | b

Source: https://www.ecfr.gov/current/title-40/chapter-I/subchapter-C/part-68/subpart-F/section-68.130

## Source

- https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.119AppA
- https://www.ecfr.gov/current/title-40/chapter-I/subchapter-C/part-68/subpart-F/section-68.130

Last verified: 2026-08-15. Review by: 2027-08-15.
Part of [OSHA PSM vs EPA RMP: chemical threshold quantities side by side](https://referencesource.org/psm-rmp-chemical-threshold-crossref/).