SACRAMENTO – The California Air Resources Board (ARB) today approved a new set of gasoline rules (https://ww3.arb.ca.gov/newsrel/ph3cbg.htm) that will ban the additive MTBE while preserving all the air-quality benefits obtained from the state's cleaner-burning gasoline program.

        "Cleaner-burning gasoline was the single-most effective measure in this decade to improve air quality," said ARB Chairman Dr. Alan Lloyd.  "Unfortunately, concern over MTBE in water has overshadowed much of that success.  These new rules will eliminate environmental risks posed by MTBE while ensuring the air-quality gains achieved with cleaner-burning gasoline will continue into the next century."

        The new rules, known officially as the Phase 3 gasoline regulation, prohibit the formulation of gasoline with MTBE after December 31, 2002.  MTBE (methyl tertiary butyl ether) helps gasoline burn more cleanly and has been extensively used in California and many other states since the early 1990s.  Like other gasoline components, MTBE poses a threat to groundwater when underground fuel tanks leak, but MTBE is more difficult to remove from water than other components and, in small amounts, renders drinking water unusable. Governor Gray Davis in March determined that MTBE in gasoline poses an unacceptable environmental threat, and he directed ARB to develop a regulation prohibiting MTBE use, while ensuring today's air-quality benefits.
 
        To better enable refiners to cost-effectively produce non-MTBE gasoline, the new regulation changes several ARB cleaner-burning gasoline specifications that have been in effect since 1996.   The regulation establishes more stringent standards for two major gasoline pollutants -- sulfur and benzene -- while relaxing two standards for distillation temperatures (which affect how cleanly gasoline burns).  The regulation also adds flexibility to Reid Vapor Pressure standard that controls gasoline's tendency to evaporate.  The new standards will improve the ability of refiners to make non-MTBE gasoline while ensuring motor vehicle emissions do not increase.  These new standards, along with the MTBE prohibition, will take effect on December 31, 2002.

        Although some non-MTBE gasoline is currently sold in certain parts of California, some refiners will need up to three years to make plant modifications needed to convert their entire production volume to non-MTBE gasoline.

        ARB today also approved an assessment that found no significant air-quality impacts are anticipated from the use of ethanol in gasoline.  Federal law currently requires gasoline in Southern California and the greater Sacramento area to contain an oxygenated additive such as MTBE or ethanol.  If the law remains in effect, gasoline in those areas as well as the San Joaquin Valley would have to contain ethanol beginning in 2003.  The Davis Administration has asked the U.S. Environmental Protection Agency to waive the requirement and make the use of ethanol optional throughout California.  A decision from U.S. EPA is pending.  With the prohibition of MTBE, ethanol use is expected to become commonplace in California even if it were not required.  However, elimination of the requirement would give refiners additional options for making cleaner-burning gasoline and would likely have a positive effect on gasoline prices.

        California's cleaner-burning gasoline reduced smog-forming emissions from motor vehicles by more than 15 percent upon its introduction in 1996, equivalent to 3.5 million cars.  The benefits from cleaner-burning gasoline continue each year, because the emission-control systems in late-model vehicles are designed to take maximum advantage of cleaner-burning gasoline's properties.  New California automobiles are up to 85 percent cleaner than new motor vehicles in 1993.

        "The use of cleaner-burning gasoline is a critical element in our efforts to provide clean air for all Californians.  Today's action will enable us to further clean our air without putting our drinking water at risk," Dr. Lloyd said.