EPA Clean Air Scientific Advisory Committee (CASAC)

Nitrogen Dioxide and Sulfur Dioxide Risk and Exposure Assessments for Secondary (Welfare-based) National Ambient Air Quality Standards (NAAQS)

EPA Designated Federal Officer (DFO):Kyndall Barry

Responsible Committee/Panel:Oxides of Nitrogen (NOx) and Sulfur Oxides (SOx) Secondary Review PanelA list of members can be found in the final report included in the Advisory Activity linked to this panel or committee.

See EPA’s PDF page to learn more about PDF files.


EPA’s Office of Air and Radiation (OAR) has requested that CASAC review draft risk and exposure assessments for the secondary (welfare-based) standards for the national ambient air quality standards for nitrogen dioxide and sulfur dioxide. The CASAC plans to review two drafts of the Agency's risk and exposure assessments.

Under the Clean Air Act, EPA is required to carry out a periodic review and revision, as appropriate, of the air quality criteria and the primary and secondary standards for six criteria air pollutants, which include nitrogen dioxide and sulfur dioxide. Secondary standards set limits to protect public welfare, including protection against decreased visibility, damage to animals, crops, vegetation, and buildings.