Fuels and Fuel Additives
EPA has several programs that establish standards for gasoline:
- Gasoline Sulfur
- The final Tier 3 Gasoline Sulfur program is part of a systems approach to addressing the impacts of motor vehicles on air quality and public health, by considering the vehicle and its fuel as an integrated system. The program sets new vehicle emissions standards to reduce both tailpipe and evaporative emissions, and lowers the sulfur content of gasoline to a 10 ppm average sulfur level.
- The Tier 2 Gasoline Sulfur program reduced the sulfur content of gasoline by up to 90 percent from uncontrolled levels. Phased in from 2004-2007, and now in effect, the program allows refiners to produce gasoline with a range of sulfur levels as long as their annual corporate average does not exceed 30 parts per million (ppm). In addition, no individual batch can exceed 80 ppm.
- The Mobile Source Air Toxics (MSAT) rules reduce hazardous air pollutants, also known as air toxics, emitted by cars and trucks. Air toxics include benzene and other hydrocarbons such as 1,3-butadiene, formaldehyde, acetaldehyde, acrolein, and naphthalene.
- Reformulated Gasoline (RFG) was mandated for metropolitan areas with the worst smog beginning in 1995. RFG is blended to burn more cleanly than conventional gasoline, reducing emissions of smog-forming and toxic pollutants.
- EPA regulates the volatility/Reid Vapor Pressure (RVP) of conventional gasoline sold at retail stations during the summer smog season (June 1-September 15) to reduce evaporative emissions that contribute to smog.
- Winter Oxygenated Fuel programs increase fuel oxygen and are mandated in certain areas for carbon monoxide control. The winter oxygenated fuel season is generally October through February or March.
- E15 is a fuel containing a mixture of gasoline and ethanol, specifically 15 volume % ethanol and 85 volume % gasoline. EPA, in response to a request by Growth Energy under section 211(f)(4) of the Clean Air Act, has granted a partial waiver to allow E15 to be introduced into commerce for use in model year 2001 and newer light-duty motor vehicles, subject to several conditions. Fuel and fuel additive manufacturers are required to register the E15 with EPA prior to beginning distribution of the fuel.
If you have questions or request information, please contact the appropriate support or help line found on the Support & Help page.
Please visit EPA's Transportation and Air Quality web-based repository of mobile source documents, Document Index System (DIS). This searchable repository contains regulations, Federal Register notices, policy letters, and guidance documents.
Please visit our Related Links page for other fuel related information within EPA, other U.S. Agencies, and other fuel related websites.