National Ambient Air Quality Standards (NAAQS): The Clean Air Act requires the Environmental Protection Agency (EPA) to set National Ambient Air Quality Standards for common air pollutants, which set limits on the concentration of these pollutants in the ambient air.
New Source Performance Standards (NSPS): The Clean Air Act authorizes the EPA to establish emission standards for new, modified, and reconstructed stationary sources of air pollution, known as New Source Performance Standards.
National Emissions Standards for Hazardous Air Pollutants (NESHAP): The Clean Air Act requires the EPA to set National Emissions Standards for Hazardous Air Pollutants, which regulate the emission of toxic air pollutants from specific industrial sources.