In 2000, EPA drafted plans to phase out the use of MTBE nationwide over four years.. Some states enacted MTBE prohibitions without waiting for federal restrictions. California banned MTBE as a gasoline additive in 2002. The State of New York banned the use of MTBE as a "fuel additive", effective in 2004. MTBE use is still legal in the state for other industrial uses.
The federal Energy Policy Act of 2005 removed the oxygenate requirement for reformulated gasoline and established a renewable fuel standard. The lack of MTBE liability protection in the law also prompted refiners to substitute ethanol for MTBE as a gasoline additive.