Startups, shutdowns, and malfunctions (SSM) are periods of non-continuous operation in refineries, chemical plants or similar industrial facilities.
Recognizing this problem, beginning in 1994 the American Environmental Protection Agency (EPA) allowed such facilities to release large amounts of otherwise prohibited air pollution during SSM.
The U.S. Court of Appeals for the District of Columbia issued a ruling on the lawsuit[3] (19 December 2008), finding that allowing such SSM exemptions does violate requirements of the Clean Air Act, in that the CAA requires that some reasonable limit on a facility's emissions of hazardous air pollutants must always be in effect.
The American Chemistry Council, a trade association of industrial and chemical manufacturing companies, joined the EPA in the court's defense actions.
An EPA spokesman said in late December 2008 that the agency is studying the decision to determine an appropriate course of action.