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.
EPA has requested CASAC review of a draft document entitled "Policy Assessment for the Review of the Secondary National Ambient Air Quality Standards for NOx and SOx: First External Review Draft (March 2010"). The Policy Assessment will serve to “bridge the gap” between the scientific information and the judgments required of the Administrator in determining whether it is appropriate to retain or revise the standards. The first draft Policy Assessment builds upon the key scientific and technical information contained in the Agency's Integrated Science Assessment for Oxides of Nitrogen and Sulfur – Ecological Criteria (EPA/600/R-08/082F) finalized December 2008 as well as the assessment document titled Risk and Exposure Assessment for Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur-Main Content - Final Report (September 2009).
|Agency Review Document(s): |
PDF for Policy Assessment for the Review of the Secondary NAAQS for NOx and SOx: First External Review Draft. (PDF, 365 pp., 8,018,615 bytes)
PDF for Policy Assessment for the Review of the Secondary National Ambient Air Quality Standards for NOx and SOx, Second External Review Draft. (PDF, 449 pp., 15,111,393 bytes)
PDF for Additional materials provided by OAQPS on September 23, 2010 for the October 6-7, 2010 CASAC Panel review of the Second Draft Policy Assessment for the NOx and SOx Secondary Standards Review. (PDF, 39 pp., 1,386,635 bytes)