IRIS Toxicological Review and Summary Documents for Toluene

Note: EPA has updated this document, but this version is provided as a courtesy to the public as a matter of public record.

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Toluene is used as an additive to gasoline mixtures (BTEX) to increase octane ratings, in benzene production, and as a solvent in paints, coatings, inks, adhesives, and cleaners. Additionally, toluene is used in the production of nylon, plastics, and polyurethanes. Toluene was once used as an anthelminthic agent against roundworms and hookworms. A large amount of toluene is released to the environment each year, mostly to the atmosphere. The largest source of toluene release is during the production, transport, and use of gasoline. Toluene has been detected in drinking water supplies, in particular in locations near leaking underground storage tanks for fuel products. Toluene has been found in soil and water in the vicinity of some hazardous waste sites. Toluene is also found in smoke from both wood and cigarettes. EPA's assessment of the carcinogenic potential and noncancer effects of toluene was entered on IRIS in the late 1980's and early 1990's. The IRIS Program has prepared an update of the assessment for toluene, which will incorporate health effects information published since finalization of the last assessment, as well as new risk assessment methods. The IRIS assessment for toluene consists of a Toxicological Review and IRIS Summary. The Toxicological Review document contains information on the physicochemical and toxicokinetic properties of the toluene; and its toxicity in humans and experimental systems. The assessment presents reference values for the noncancer effects of toluene (RfD and RfC), where supported by available data, and a cancer evaluation. The Toxicological Review and IRIS Summary were subject to internal peer consultation, Agency review and two external scientific peer review. The final product reflects the Agency's opinion on the toxicity of toluene.