Air Pollution Emissions During Startups, Shutdowns, and Malfunctions

Air pollution emission limitations on stationary sources are usually based on what is achievable during normal operation, but these requirements cannot always be met during the startup or shutdown of either specific processes or the entire facility. Moreover, malfunctions occur even at facilities that are well designed and operated. How startup, shutdown, and malfunction (SSM) events should be handled under the Clean Air Act (CAA) is controversial. The issue is complicated by the fact that under the CAA the implementation and enforcement of the Act is usually delegated to the states, which have parallel requirements in their federally approved state implementation plans as well as in their state permit program regulations.