# Methyl mercaptan — US federal chemical regulatory reporting thresholds by program (CERCLA, EPCRA, CAA)

For Methyl mercaptan, cas no. is 74-93-1; cercla rq (lbs) is 100; rcra waste number is U153; regulatory categories is 1,4, verified against its source on 2026-08-05.

- **Substance:** Methyl mercaptan _(verified: appears in the quote below)_
- **CAS No.:** 74-93-1 _(verified: appears in the quote below)_
- **CERCLA RQ (lbs):** 100 _(verified: appears in the quote below)_
- **RCRA waste number:** U153 _(verified: appears in the quote below)_
- **Regulatory categories:** 1,4 _(verified: appears in the quote below)_
- **EPCRA TPQ (lbs):** 500 _(per ecfr.gov, not stated by the source above)_
- **EPCRA RQ (lbs):** 100 _(per ecfr.gov, not stated by the source above)_

## What the source says

> Methyl mercaptan | 74-93-1 | 1,4 | U153 | 100 (45.4)

## What ecfr.gov says

> 500 | 74-93-1 | Methyl Mercaptan | f | 100 |

Source: https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-355

## Source

- https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-302/section-302.4
- https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-355

Last verified: 2026-08-05. Review by: 2027-08-05.
Part of [US federal chemical regulatory reporting thresholds by program (CERCLA, EPCRA, CAA)](https://referencesource.org/chemical-regulatory-reporting-thresholds/).