Oxygenates (e.g., methyl tertiary butyl ether [MTBE], ethanol) are required in certain areas of the United States by the 1990 Clean Air Act Amendments. MTBE and ethanol have also been used to increase octane ratings in U.S. gasoline since the 1970s. In 1996 alone, 10 billion Kg MTBE and 3 billion Kg ethanol were used in U.S. fuel.

Contamination of water resources by fuel oxygenates raises several issues that are difficult to evaluate with currently available information. The sources, pathways, and extent of actual and potential exposure of human populations are not adequately known. Quantitative characterization of health risks is problematic. Moreover, independent of the degree of human health risk that may be posed by oxygenates in water, the sensory properties of contaminated water may override health concerns. These and other issues are highlighted in a document recently released by EPA, "Oxygenates in Water: Critical Information and Research Needs," the purpose of which is to identify work needed to provide a better basis for characterizing the potential health and environmental risks of oxygenates and for informing risk management and policy decision making. As the document notes, if the environment and public health are to be protected effectively and efficiently, adequate scientific information and technical data are essential.


Davis, J. FUEL OXYGENATES HEALTH ISSUES. Presented at American Water Works Assoc. Meeting, Chicago, IL, June 22, 1999.