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

For Hydrogen cyanide, cas no. is 74-90-8; cercla rq (lbs) is 10; rcra waste number is P063; regulatory categories is 1,4, verified against its source on 2026-08-05.

- **Substance:** Hydrogen cyanide _(verified: appears in the quote below)_
- **CAS No.:** 74-90-8 _(verified: appears in the quote below)_
- **CERCLA RQ (lbs):** 10 _(verified: appears in the quote below)_
- **RCRA waste number:** P063 _(verified: appears in the quote below)_
- **Regulatory categories:** 1,4 _(verified: appears in the quote below)_

## What the source says

> Hydrogen cyanide | 74-90-8 | 1,4 | P063 | 10 (4.54)

## Source

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

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/).