The Clean Air Act Amendments of 1990 were signed into law as P.L. 101-549 on November 15, 1990. This was the most recent of three significant development in environmental legislation in years, along with the Clean Air Act of 1970 and the 1977 Clean Air Act Amendments.
The 1990 Amendments contain 7 separate titles covering different regulatory programs. They created many new regulatory requirements; from installation of more advanced pollution control equipment, changes in industrial operations and to even community lifestyle to cause reductions in emissions of air pollutants.
The basic framework of the Clean Air Act (CAA) remains basically constant, but the 1990 Amendments do significantly alter and add to the regulatory requirements.