VOC

Volatile Organic Compounds (VOCs) are organic chemical compounds that have high enough vapor pressures under normal conditions to significantly vaporize and enter the atmosphere. A wide range of carbon-based molecules, such as aldehydes, ketones, and other light hydrocarbons are VOCs.

The U.S. Environmental Protection Agency definition of VOCs is published in the Code of Federal Regulations.

 It defines VOCs as "any compound of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonate, which participates in atmospheric photochemical reactions," but also includes a list of dozens of exceptions for compounds "determined to have negligible photochemical reactivity."

VOCs are sometimes accidentally released into the environment, where they can damage soil and groundwater. Vapours of VOCs escaping into the air contribute to air pollution.

VOCs are an important outdoor air pollutant. In this field they are often divided into the separate categories of methane ((CH₄) and non-methane (NMVOCs). Methane is an extremely efficient greenhouse gas which contributes to enhanced global warming. Other hydrocarbon VOCs are also significant greenhouse gases via their role in creating ozone and in prolonging the life of methane in the atmosphere, although the effect varies depending on local air quality. Within the NMVOCs, the aromatic compounds benzene, toluene and xylene are suspectedcarcinogens and may lead to leukemia through prolonged exposure. 1,3-butadiene is another dangerous compound which is often associated with industrial uses.

Some VOCs also react with nitrogen oxides in the air in the presence of sunlight to form ozone. Although ozone is beneficial in the upper atmosphere because it absorbs UV thus protecting humans, plants, and animals from exposure to dangerous solar radiation, it poses a health threat in the lower atmosphere by causing respiratory problems. In addition high concentrations of low level ozone can damage crops and buildings.

Please read this article:  How to Choose the Best Drinking Water Filter

Back to Glossary