Californian authority has delayed for one year the state's deadline for banning the fuel additive methyl tert-butyl ether (MTBE). The decision to postpone the ban until January 1, 2004, follows release of a report by the Californian Energy Commission shown the ban could increase gasoline prices by 50% to 100%. The Governor of California has ordered the MTBE phaseout after regulators found it had contaminated drinking water supplies, prompting complaints about the taste and concerns about potential health problems. Studies show that MTBE in large doses could cause cancer in animals, but its effect on humans is still unknown.