Is there any guidance that clarifies what is meant by “a quantity sufficient to present a danger to human health or the environment” from 40 CFR 261.23 discussing the characteristic of reactivity for cyanide or sulfide waste?
EPA received many comments regarding the proposed rule for the identification and listing of hazardous waste and the inclusion in the reactivity definition of "any cyanide or sulfide bearing waste which can generate toxic gases, vapors or fumes when exposed to mild acidic or basic conditions."
EPA clarified the language from the proposed rule by including only those cyanide or sulfide bearing wastes "which generate toxic gases, vapors and fumes in a quantity sufficient enough to present a danger to human health or the environment." EPA also specified that "mild acidic or basic conditions" refers to pH conditions between 2 and 12.5.
Although there are no known test methods for accurately measuring reactivity, the narrative statement clearly provides guidance on the description of the reactivity characteristic. In addition, most generators of reactive wastes are aware that their wastes possess this property and require special handling. This is because such wastes are dangerous to the generator's own operations and are rarely generated from unreactive feed stocks.