---
title: "How must a business determine if its waste is hazardous? Answer in under 100 words. Cite only eCFR (www.ecfr.gov) sources."
canonical: https://www.m-i-n-d.ai/minds/environmental/hazardous-waste-determination
jurisdiction: "US Federal"
last_verified: 2026-08-27
license: CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/
attribution: "Source: MIND (m-i-n-d.ai)"
---

# How must a business determine if its waste is hazardous? Answer in under 100 words. Cite only eCFR (www.ecfr.gov) sources.

Under 40 CFR 262.11, effective November 28, 2016, a waste generator must determine whether each solid waste is hazardous using a step-by-step process: first check exclusions under 40 CFR 261.4, then use knowledge of the waste to see if it matches any listing in Subpart D of 40 CFR Part 261, and finally test or use knowledge to determine if it exhibits a characteristic in Subpart C of 40 CFR Part 261.

## How the determination works

A waste generator makes a hazardous waste determination at the point of generation, before any dilution, mixing, or alteration, and again if the waste's properties may change during management. The steps, in order, are:

1. **Check exclusions** — determine whether the solid waste is excluded from regulation under 40 CFR 261.4.
2. **Check listings** — using knowledge of waste origin, composition, feedstock, and the generating process, determine whether the waste matches any listing in Subpart D of 40 CFR Part 261.
3. **Check characteristics** — using knowledge, testing, or both, determine whether the waste exhibits any characteristic (ignitability, corrosivity, reactivity, or toxicity) in Subpart C of 40 CFR Part 261. Testing must use a representative sample as defined at 40 CFR 260.10 and the methods specified in Subpart C, or an equivalent method approved by the EPA Administrator under 40 CFR 260.21.

## Recordkeeping requirements

Small quantity generators and large quantity generators must keep records supporting each determination — including test results, sampling/analytical methods, waste composition, and the knowledge basis — for at least three years from the date the waste was last sent to on-site or off-site treatment, storage, or disposal. Retention is automatically extended during any unresolved enforcement action or at the request of the EPA Administrator.

## If the waste is hazardous

Once a waste is determined to be hazardous, the generator must identify all applicable EPA hazardous waste numbers from Subparts C and D of 40 CFR Part 261 and mark the containers with those numbers before shipping off site, in accordance with 40 CFR 262.32. The generator must also consult 40 CFR Parts 261, 264, 265, 266, 267, 268, and 273 for any additional exclusions or restrictions on management of the specific waste.

## Exceptions & edge cases

- **Listed wastes from a specific site** — A generator may file a delisting petition under 40 CFR 260.20 and 40 CFR 260.22 asking the EPA Administrator to rule that the waste from that particular site is not hazardous.
- **Alternative test methods** — A test other than those in Subpart C may be used as part of the generator's knowledge, but it does not, by itself, provide a definitive result. Definitive results come only from properly performed regulatory tests under Subpart C, or from an equivalent method approved under 40 CFR 260.21.
- **Representative sampling** — Any testing requires a representative sample as defined at 40 CFR 260.10.

## Sources

- [1] U.S. Government Publishing Office / Environmental Protection Agency — 40 CFR 262.11 — Hazardous waste determination and recordkeeping for generators · https://www.ecfr.gov/current/title-40/section-262.11 · as of 2026-08-27