In setting primary and secondary national ambient air quality standards (NAAQS), the EPA's responsibility under the law is to establish standards that protect public health and welfare. The Clean Air Act (the Act) requires the EPA, for each criteria pollutant, to set a standard that protects public health with “an adequate margin of safety and public welfare from “any known or anticipated adverse effects. As interpreted by the Agency and the courts, the Act requires the EPA to base the decision for the primary standard on health considerations only; economic factors cannot be considered. The prohibition against considering cost in the setting of the primary air quality standards does not mean that costs, benefits or other economic considerations are unimportant. The Agency believes that consideration of costs and benefits is an essential decision-making tool for the efficient implementation of these standards. The impacts of costs, benefits, and efficiency are considered by the States when they make decisions regarding what timelines, strategies, and policies are appropriate for their circumstances.

EPA Project Officer: Robin Langdon. Includes bibliographical references. "EPA-452/R-15/007." PB2016-100071.