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Protecting Clean Air 

The Clean Air Act, which was last amended in 1990, requires EPA to set National Ambient Air Quality Standards (NAAQS - pronounced "nacks") for pollutants considered harmful to public health and the environment. The Clean Air Act identifies two types of standards for ambient (outdoor) air:

  • A primary standard, designed to protect public health 
  • A secondary standard, designed to protect public welfare. Welfare includes damage to plants and animals, impairment of visibility, and property damage.


National Ambient Air Quality Standards
PollutantAveragePrimary StandardSecondary StandardKY Attainment Status
Carbon Monoxide8-hour average9 ppmsame as primaryAttainment/unclassifiable statewide
Carbon Monoxide1-hour35 ppmsame as primaryAttainment/unclassifiable statewide
Sulfur Dioxide1-hour75 ppbsame as primaryHenderson & Webster partial nonattainment
Sulfur Dioxide3-hournone0.50 ppmAttainment/unclassifiable statewide
Nitrogen DioxideAnnual53 ppbsame as primaryAttainment/unclassifiable statewide
Nitrogen Dioxide1-hour100 ppbsame as primaryAttainment/unclassifiable statewide
LeadRolling 3-month average0.15 ug/m3same as primaryAttainment/unclassifiable statewide
Ozone8-hour average0.070 ppmsame as primaryBullitt, Jefferson, Oldham moderate nonattainment (*EPA has not acted on attainment redesignation for these counties)
PM1024-hour average150 ug/m3same as primaryAttainment/unclassifiable statewide
PM2.524-hour average35 ug/m3same as primaryAttainment/unclassifiable statewide
PM2.5Annual average9 ug/m315 ug/m3Attainment/unclassifiable statewide
Kentucky Energy and Environment Cabinet
300 Sower Blvd
Frankfort, KY 40601

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Civil Rights/Derecho Civiles

The Kentucky Energy and Environment Cabinet does not discriminate against any person on the basis of race, color, national origin, religion, age, disability or sex. This policy protects the rights of Cabinet employees, service applicants and customers. Vendors, agencies and organizations providing services to the Cabinet or its recipients of federally-aided programs also must comply with this policy.