---
kind: "section"
citation: "40 C.F.R. § 261.23"
title: "40"
number: "261.23"
heading: "Characteristic of reactivity."
url: "https://uscodex.org/cfr/40/261.23"
---

# §261.23. Characteristic of reactivity.

- (a) A solid waste exhibits the characteristic of reactivity if a representative sample of the waste has any of the following properties:
  - (1) **It is normally unstable and readily undergoes violent change without detonating.**
  - (2) **It reacts violently with water.**
  - (3) **It forms potentially explosive mixtures with water.**
  - (4) When mixed with water, it generates toxic gases, vapors or fumes in a quantity sufficient to present a danger to human health or the environment.
  - (5) It is a cyanide or sulfide bearing waste which, when exposed to pH conditions between 2 and 12.5, can generate toxic gases, vapors or fumes in a quantity sufficient to present a danger to human health or the environment.
  - (6) It is capable of detonation or explosive reaction if it is subjected to a strong initiating source or if heated under confinement.
  - (7) It is readily capable of detonation or explosive decomposition or reaction at standard temperature and pressure.
  - (8) It is a forbidden explosive as defined in [49 CFR 173.54](/cfr/49/173.54.md), or is a Division 1.1, 1.2 or 1.3 explosive as defined in 49 CFR [173.50](/cfr/49/173.50.md) and [173.53](/cfr/49/173.53.md).
- (b) A solid waste that exhibits the characteristic of reactivity has the EPA Hazardous Waste Number of D003.

## Notes

### Amendments

[45 FR 33119, May 19, 1980, as amended at 55 FR 22684, June 1, 1990; 75 FR 13002, Mar. 18, 2010]

### Authority

Authority: 42 U.S.C. 6905, 6912(a), 6921, 6922, 6924(y) and 6938.

### Source

Source: 45 FR 33119, May 19, 1980, unless otherwise noted.

### Amendments

[45 FR 33119, May 19, 1980, as amended at 55 FR 22684, June 1, 1990; 75 FR 13002, Mar. 18, 2010]