Fuels and Fuel Additives
State Winter Oxygenated Fuel Program
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Oxygenates are fuel additives that contain oxygen, usually in the form of alcohol or ether. Oxygenates can enhance fuel combustion and thereby reduce exhaust emissions. Some oxygenates also boost gasoline octane.
The Clean Air Act requires use of oxygenated gasoline in areas where winter time carbon monoxide levels exceed federal air quality standards. Without oxygenated gasoline, carbon monoxide emissions from gasoline-fueled vehicles tend to increase in cold weather. Winter oxygenated gasoline programs are implemented by the states. The links below provide information about oxygenated gasoline, winter oxygenated gasoline areas, oxygenates (such as ethanol and MTBE), and health effects testing of oxygenates.
Guidance and Background Documents
- State Winter Oxygenated Fuel Program Requirements for Attainment or Maintenance of CO NAAQS (PDF) (6 pp, 82K, EPA420-B-08-006, January 2008) List of locations with winter oxygenated fuel programs.
Report: Interagency Assessment of Oxygenated Fuels. (July 2, 1997) The White House Office of Science and Technology Policy final report on EPA's winter oxygenated fuels program. The report considers health effects, air quality, fuel economy and engine performance, and ground water and drinking water quality issues.
- Memo: Water Phase Separation in Oxygenated Gasolines (PDF) (6 pp, 15K, Feb. 27, 1996)
- Oxyfuels Information Needs - May 1996 Office of Research & Development (ORD) report This report discusses information that would improve scientific understanding of the impacts of oxygenated fuels on the environment and public health.
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Please visit our Related Links page for other fuel related information within EPA, other U.S. Agencies, and other fuel related websites.