Nitrogen Dioxide (NO2) and Sulfur Dioxide (SO2) Secondary Standards
Due to the government shutdown in October 2013, the planning workshop originally scheduled for October 1 to 3, 2013 has been postponed until the Spring 2014. Additional details will follow when they are available.
The Clean Air Act requires EPA to set national air quality standards for six criteria pollutants (nitrogen oxides, sulfur oxides, particulate matter, ozone, carbon monoxide, and lead) based on primary (health-based) and secondary (welfare-based) considerations. The law also requires EPA to periodically review the scientific criteria upon which the standards are based (learn more about this process). While EPA generally reviews criteria and standards for each of the six criteria pollutants individually, for this review of the secondary standards for NO2 and SO2, EPA has decided to examine nitrogen oxide (NOx) and sulfur oxide (SOx) compounds together. EPA recognizes that NOx, SOx are inextricably linked from both an atmospheric chemistry and environmental effects perspectives.
Documents from Current Review
- Planning Documents
- Integrated Science Assessments
- Risk and Exposure Assessments
- Policy Assessments
- Other Technical Documents
- CASAC Documents
- Federal Register Notices
- Response to Comments Document
- Regulatory Impact Analysis