The US Environmental Protection Agency (EPA) is proposing to remove the affirmative defense provisions associated with violation of emission standards due to malfunctions. This proposal is part of a series of affirmative defense removals following a 2014 decision from the D.C. Circuit Court (PDF), which vacated an affirmative defense provision under Clean Air Act Section 112. Since the court decision, the EPA has been removing affirmative defense provisions from CAA rules when they were otherwise revised or amended.

Comments on the proposal must be received before August 8, 2024. Written comments may be submitted via the Federal eRulemaking Portal or via email to