Criteria air contaminants

Criteria air contaminants (CAC), or criteria pollutants, are a set of air pollutants that cause smog, acid rain and other health hazards. The laws and regulations of different polities may define different sets. CACs are typically emitted from many sources in industry, mining, transportation, electricity generation and agriculture. In most cases they are the products of the combustion of fossil fuels or industrial processes.

Contents

Definitions

United States

Criteria air contaminants were the first set of pollutants recognized by the United States Environmental Protection Agency as needing standards on a national level. [1] The US National Ambient Air Quality Standards (NAAQS) requires the EPA to set standards on six CACs:[2]

  1. Ozone (O3)
  2. Particulate Matter
    • PM10, coarse particles: 2.5 micrometers (μm) to 10 μm in size (although current implementation includes all particles 10 μm or less in the standard)
    • PM2.5, fine particles: 2.5 μm in size or less
  3. Carbon monoxide (CO)
  4. Sulfur dioxide (SO2)
  5. Nitrogen oxides (NOx)
  6. Lead (Pb)

The US regulates volatile organic compounds (VOCs), but not as CACs.

Canada

Canadian regulations include among CACs those species regulated by the US, plus volatile organic compounds (VOCs).[3]

References

  1. ^ Michigan Department Of Environmental Quality, January 2004. What is an Air Contaminant Pollutant? Fact Sheet.
  2. ^ http://epa.gov/air/criteria.html US EPA
  3. ^ http://www.ec.gc.ca/cleanair-airpur/Pollutants/Criteria_Air_Contaminants_and_Related_Pollutants-WS7C43740B-1_En.htm Environment Canada

See also

External links