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

For Selenious acid, cas no. is 7783-00-8; cercla rq (lbs) is 10; rcra waste number is U204; regulatory categories is 4, verified against its source on 2026-08-05.

- **Substance:** Selenious acid _(verified: appears in the quote below)_
- **CAS No.:** 7783-00-8 _(verified: appears in the quote below)_
- **CERCLA RQ (lbs):** 10 _(verified: appears in the quote below)_
- **RCRA waste number:** U204 _(verified: appears in the quote below)_
- **Regulatory categories:** 4 _(verified: appears in the quote below)_
- **EPCRA TPQ (lbs):** 1,000/10,000 _(per ecfr.gov, not stated by the source above)_
- **EPCRA RQ (lbs):** 10 _(per ecfr.gov, not stated by the source above)_

## What the source says

> Selenious acid | 7783-00-8 | 4 | U204 | 10 (4.54)

## What ecfr.gov says

> 10 | 7783-00-8 | Selenious Acid | | 10 | 1,000/10,000 |

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/).