1999 Cancer Potency Assessment of Methyl-tert-butyl ether

The Office of Environmental Health Hazard Assessment (OEHHA) has been requested by the Air Resources Board (ARB) to develop health values for the inhalation pathway for the Toxic Air Contaminant, methyl tertiary-butyl ether (MTBE). MTBE is a toxic air contaminant identified by the ARB in 1993 pursuant to Health and Safety Code Section 39657(b). MTBE was evaluated by OEHHA under the drinking water Public Health Goals (PHG) program. OEHHA developed a cancer slope factor for MTBE which underwent public comment and peer review. OEHHA is using that documentation as the basis for a cancer unit risk factor for MTBE for use in air programs. The documentation is available for public review for a 30-day period commencing July 9 and ending August 9, 1999. The document is available from the download area below.

Please direct all comments to:

Office of Environmental Health Hazard Assessment
1515 Clay St., 16th Floor
Oakland, CA 94612

Phone inquiries regarding the assessment can be directed to: (510) 622-3150.