Affirmative defense
Affirmative defense means, in the context of an enforcement proceeding, a response or a defense put forward by a defendant, regarding which the defendant has the burden of proof, and the merits of which are independently and objectively evaluated in a judicial or administrative proceeding. Beginning on July 15, 2024, this definition of affirmative defense no longer applies.
Source
40 CFR § 63.482
Scoping language
The following terms used in this subpart shall have the meaning given them in 63.2, 63.101, or the Act, as specified after each term: