Volatile organic compounds (VOC) are carbon-containing gases and vapors such as gasoline fumes and solvents (but excluding carbon dioxide, carbon monoxide, methane, and chlorofluorocarbons). Although there are many thousands of organic compounds in the natural and polluted troposphere that meet the definition of a VOC, most measurement programs have concentrated on the 50 to 150 most abundant hydrocarbons.

Many individual VOC are known or suspected of having direct toxic effects on humans, ranging from carcinogenesis to neurotoxicity. A number of individual VOC (e.g. benzene, dichloromethane) have been assessed to be toxic under the Canadian Environmental Protection Act, 1999 (CEPA 1999). The more reactive VOC combine with nitrogen oxides (NOx) in photochemical reactions in the atmosphere to form ground-level ozone, a major component of smog. VOC are also a precursor pollutant to the secondary formation of fine particulate matter (PM_2.5). Both ozone and PM_2.5 are known to have harmful effects on human health and the environment.

For more detailed information about VOC, visit http://www.ec.gc.ca/nopp/voc/en/index.cfm

Related Websites:

http://www.ccme.ca/ourwork/air.html
http://www.ec.gc.ca/air/interim2001/minister_e.html
http://www.ec.gc.ca/CEPARegistry/default.cfm
http://www.ec.gc.ca/cleanair-airpur/Canada_US
http://www.unece.org/env/lrtap/