Frequent Questions

For the purposes of determining whether a waste meets the characteristic of ignitability, how does EPA define an ignitable compressed gas or an oxidizer?

In defining the ignitability characteristic, EPA incorporates by reference the definition of the terms ignitable compressed gases and oxidizers provided in 49 CFR §173.300 and §173.151 (§§261.21(a)(3) and (4)). In addition, §261.21(a)(3) should refer to “flammable compressed gases” rather than “ignitable compressed gases”. (RCRA Online #12164)).

Additional guidance on ignitable oxidizers is provided in the June 1, 1990, Federal Register (55 FR 22520, 22546; OSW-FR-90-010) and July 14, 2006 Federal register (71 FR 40259), available at the following URL:


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