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Study: MTBE Poses Limited Threat to Health and the Environment

The scheduled phase-out of methyl tertiary butyl ether or MTBE in California now appears to be unnecessary and economically risky, according to a new European study.

The study has effectively cleared the cleaner burning gasoline additive MTBE of allegations that it poses a significant risk to health or the environment.

The Commission of European Communities, Europe's official scientific investigative body, released findings from a comprehensive study of MTBE health effects. The Commission concluded that MTBE poses very limited risks that can be essentially mitigated by existing control mechanisms such as sound fuel tank management and code enforcement. The Commission found, "no compelling reasons to limit use (of MTBE) in motor fuel."

The European Commission's findings are significant because they validate the findings of World Health Organization's International Agency for Research on Cancer, the U.S. National Toxicology Panel, California's Science Advisory Board for Proposition 65, and several other studies that all agree there is no compelling evidence that MTBE causes cancer in human beings.

In addition, updated, cumulative statistics from the California Department of Health Services indicate that the actual detections of MTBE in drinking water have been extremely small - less than 1 percent of the water sources tested - and the trends have declined to very low levels. This marked improvement, say experts, is due to advances made in upgrading underground gasoline storage tanks and better tank program enforcement throughout the state.

"The European Commission is yet another credible scientific body that has declared MTBE safe, given rigorous enforcement of the underground gasoline storage tank program. Better enforcement in California is now preventing gasoline leaks into groundwater. So why are we phasing out MTBE?" commented James White, principal of White Environmental Associates.

Governor Gray Davis' decree that MTBE be phased out of California gasoline by 2003 was based largely on two projections:

  • That MTBE was a pervasive groundwater contaminant throughout the state, and
  • That MTBE posed a health threat to Californians.

The governor now is considering whether to extend the deadline of an MTBE phase-out due to supply and transportation problems associated with importing ethanol (MTBE's primary alternative) to California.

Earlier this year, the California Energy Commission concluded that a switch from MTBE to ethanol in California gasoline would result in significant gasoline price spikes. Governor Davis has stated publicly that ethanol-related price spikes at the gas pump could be as high as fifty cents per gallon.

For copies of the European Commission study on MTBE, and a link to California Department of Health Services groundwater monitoring data, click on "Studies and Presentations" at

edited by Sandy Smith ([email protected])

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