The Clean Air Act is a United States federal law designed to control air pollution on a national level.[1] It is one of the United States' first and most influential modern environmental laws, and one of the most comprehensive air quality laws in the world.[2][3] As with many other major U.S. federal environmental statutes, it is administered by the U.S. Environmental Protection Agency (EPA), in coordination with state, local, and tribal governments.[4] Its implementing regulations are codified at 40 C.F.R. (10 St. 51 Min, 6 Mai 1990 Jahr – 11 St. 14 Min, 16 Aug 1990 Jahr)