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Environmental Health - Toxic Substances



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BTEX - "BTEX is the term used for benzene, toluene, ethylbenzene, and xylene-volatile aromatic compounds typically found in petroleum product, such as gasoline and diesel fuel." - Environmental Protection Agency, 2010

BTEX (benzene, toluene, ethylbenzene, and xylene) - "Volatile, monocyclic aromatic compounds present in coal tar, petroleum products, and various organic chemical product formulations (Cohen and Mercer, 1993). These are the most soluble of the major gasoline compounds and, therefore, are common indicators of gasoline contamination." - Wilson and Moore, 1998

BTEX (benzene, toluene, ethylbenzene, and xylene) - "BTEX is a group of chemicals which is quantified by one analytical method...Toluene, ethylbenzene, and the three isomers of xylene are colourless liquids, immiscible with water but miscible with organic solvents. They have a characteristic strong odour and are highly flammable." - European Environment Agency, 2010

Related Definitions

Volatile Organic Compounds (VOCs)

USGS Toxic Substances Hydrology Program Research on BTEX and other VOCs

USGS Toxic Substances Hydrology Program Remediation of BTEX and other VOC-Related Activities

USGS Information on VOCs

Related Science Feature Articles

Frequently Asked Questions (FAQs)

BTEX Toxicological Information from the Agency for Toxic Substances and Disease Registry


Cohen, R.M., and Mercer, J.W., 1993, DNAPL site evaluation: C.K Smoley, 384 p.

European Environment Agency, 2010, Benzene, toluene, ethylbenzene, xylene (as BTEX): European Environment Agency, access date May 26, 2010.

U.S. Environmental Protection Agency, 2010, Waste and cleanup risk assesment glossary: U.S. Environmental Protection Agency, access date May 26, 2010.

Wilson, W.E., and Moore, J.E., 1998, Benzene, toluene, ethylbenzene, xylene, in Wilson, W.E., and Moore, J.E., eds., Glossary of Hydrology: Alexandria, Virginia, American Geological Institute, p. 20.


Disclaimer: The definitions on this page are provided for information purposes only, and do not indicate endorment by the U.S. Geological Survey.

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