See EPA’s PDF page to learn more about PDF files.
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 oxides of nitrogen (NOx). EPA is currently reviewing the primary (health-based) standard for the Nitrogen Dioxide National Ambient Air Quality Standards (NAAQS).
EPA’s Office of Research and Development has requested consultative advice on its Draft Plan for Development of the Integrated Science Assessment (ISA) for NOx. The final Integrated Science Assessment is intended to provide a synthesis and evaluation of science relevent for reviewing and revising the primary (health-based) standard for the Nitrogen Dioxide NAAQS.