Frequent Questions

What federal requirements result in cleaner-burning gasoline?
Are states and local areas allowed to have clean gasoline requirements that differ from Federal requirements?
Why do some states want different clean gasoline programs than the Federal program?
What are states and local areas required to do to get their own clean fuel program?
Do different state and local clean fuel requirements cause gas supply problems?

Q.What federal requirements result in cleaner-burning gasoline?

A. In highly polluted areas of the country the Clean Air Act requires that only a special type of gasoline known as reformulated gasoline (RFG) be sold and used. RFG must meet specific emission performance standards to ensure that it is cleaner burning gasoline. In addition to these standards, RFG is also subject to the recently promulgated Tier 2/low sulfur gasoline regulations. In other areas of the country, conventional gasoline (CG) is used. As is the case with RFG, CG is subject to the Tier 2/low sulfur gasoline regulations. All gasoline, whether CG or RFG, must meet requirements that limit the Reid Vapor Pressure (RVP) of gasoline to a maximum of 9.0 psi throughout the 48 contiguous states during the summer ozone season. The Clean Air Act also authorizes EPA to set more stringent RVP limits for nonattainment areas. EPA has published rules for such areas; these regulations limit the RVP of gasoline in such areas to a maximum of 7.8 psi during the "high ozone season", from June 1 to September 15 of each year.

Q. Are states and local areas allowed to have clean gasoline requirements that differ from Federal requirements?

A. The Federal gasoline requirements in the Clean Air Act takes precedence, except under certain circumstances where the Act allows states to implement their own clean fuel programs. (In the case of California, that is the only state that is allowed under the Act to establish its own controls on motor vehicle fuels). Right now, there are fifteen states that have their own clean fuel program, providing cleaner air to millions more people than would otherwise occur. Some states like New York and Connecticut have the federal RFG program, but have banned the gasoline additive MTBE which is used to provide oxygen in the fuel. Since RFG must contain a minimum of 2 percent oxygen by weight and MTBE is banned in these states, the oxygen must be supplied to the RFG by another additive. The only other additive that is used by refiners in the U.S. is ethanol. Thus, although it meets the federal requirements, RFG in states that ban MTBE is different from RFG in states that do not ban MTBE because of the different oxygenate used in the fuel.

Q. Why do some states want different clean gasoline programs than the Federal program?

A. The federal gasoline program results in cleaner air. But sometimes states need to obtain even more emission reductions than can be achieved by meeting the federal standards. For example, some states require CG in nonattainment areas to have lower volatility than the required 7.8 psi federal gasoline standards because they want the benefit of lower VOC emissions. In other cases, local fuel providers have worked with states to develop an alternative fuel specification that achieves more emissions reductions than federal RFG.

Q. What are states and local areas required to do to get their own clean fuel program?

A. States use their State Implementation Plan, or SIP, to achieve the NAAQS. The SIP contains many emission control measures. EPA may approve a state fuel control into a SIP if EPA finds the state fuel control is necessary to achieve the NAAQS, which the SIP implements. (NAAQS exist for each of the six "criteria" pollutants, i.e., ozone, nitrogen dioxide, carbon monoxide, particulate matter, sulfur dioxide, and lead.) Such approvals must be based on a demonstration that no other measures would bring about timely attainment of the NAAQS, or if other measures exist, they are unreasonable or impracticable.

Q. Do different state and local clean fuel requirements cause gas supply problems?

A. Unchecked, a patchwork quilt of differing fuel programs has the potential to cause price or supply difficulties. This is why states considering such controls typically conduct a public advisory process to consult with stakeholders, including refiners and fuel suppliers who serve the affected region, and other members of the public. Refiners typically have worked with the states to design fuel controls that met the region's air quality needs at the least possible cost. The state and local fuel programs, therefore, are typically a joint effort between the refiners and suppliers, and the public and the state environmental agencies. Fuel supply and cost are important considerations when designing the program.