Federal lawmakers in the US have unveiled a bill called the Clean Air and Water Preservation Act, which would ban methyl tertiary butyl ether (MTBE) -- an additive used in petrol to increase the oxygen content -- in a phased manner over the next three years. The bill would also promote the use of ethanol, an environmentally friendly grain-based fuel. Says Greg Ganske, a Republican from Iowa who co-authored the measure: "The bill addresses the harms caused by MTBE and focuses on the development of renewable fuels, like ethanol."
The use of MTBE as a fuel additive became widespread after 1990, when an amendment to the federal Clean Air Act required refineries to blend an oxygenate into petrol sold in urban areas with unhealthy levels of air pollution. Most chose MTBE over other oxygenates, since the substance was easily available, blended easily and was cost effective.
"Ethanol is a clean, renewable alternative to MTBE," said John Shimkus, a Republican who co-authored the bill. "With ethanol there are none of the problems that are associated with MTBE, such as groundwater contamination."
Some lawmakers have begun to question the soundness of requiring any oxygenate additives for gasoline. The drumbeat for that argument is especially strong in California, a state implementing the strongest emissions standards in the world. California has already passed a law that bans MTBE after December 31, 2002. California officials have asked that the federal oxygenate requirement be waived altogether.