The Clean Air Act is the law that defines EPA's responsibilities for protecting and improving the nation's air quality and the stratospheric ozone layer. The last major change in the law, the Clean Air Act Amendments of 1990, was enacted by Congress in 1990. Legislation passed since then has made several minor changes.
The Clean Air Act, like other laws enacted by Congress, was incorporated into the United States Code as Title 42, Chapter 85. The House of Representatives maintains a current version of the U.S. Code, which includes Clean Air Act changes enacted since 1990.
EPA's website (at https://www.epa.gov/clean-air-act-overview/clean-air-act-text) provides links to sections of the U.S. Code containing the amended text of the Clean Air Act, as well as further information about the Act itself. Visit https://www.epa.gov/clean-air-act-overview/clean-air-act-text to learn more.