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Reviewing National Ambient Air Quality Standards (NAAQS)
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Sulfur Dioxide (SO2) Primary Air Quality Standards

The Clean Air Act requires EPA to set national ambient air quality standards (NAAQS) for sulfur dioxide and five other pollutants considered harmful to public health and the environment (the other pollutants are ozone, particulate matter, nitrogen dioxide, carbon monoxide, and lead). The law also requires EPA to periodically review the standards to ensure that they provide adequate health and environmental protection, and to update those standards as necessary. Learn more about the NAAQS review process.

Documents from Current Review

  • Planning Documents
  • Integrated Science Assessments
  • Risk and Exposure Assessments
  • Policy Assessments
  • Other Technical Documents
  • CASAC Documents
  • Federal Register Notices
  • Litigation

Documents from Previous Reviews

  • Documents from Review Completed in 2010
  • Documents from Reviews Completed Prior to 2010

Related Links

  • Air Quality Research
  • Criteria Air Pollutants
  • Table of Current NAAQS
  • Timeline of SO2 NAAQS
  • Air Quality Analysis
  • Trends and Design Values
  • Reviewing NAAQS - Scientific and Technical Information Home
  • Carbon Monoxide Standards
  • Lead Standards
  • Nitrogen Dioxide Primary Standards
  • Nitrogen Dioxide Secondary Standards
  • Ozone Standards
  • Particulate Matter Standards
  • Sulfur Dioxide Primary Standards
  • Sulfur Dioxide Secondary Standards
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on January 18, 2022
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