Gasoline additive’s going, but far from gone

Last month, the Environmental Protection Agency announced plans to phase down, and perhaps out, use of a suspected carcinogen that refiners have added to gasoline since the 1970s.

An octane booster, methyl tert-butyl ether—better known as MTBE—also reduces a vehicle’s emissions of carbon monoxide and ozone. Owing to myriad gasoline leaks, however, MTBE now taints drinking-water supplies throughout the nation.