Reformulated Gasoline Program
- Texas Counties Required to Use RFG
- The Difference Between Oxygenated Gasoline and RFG
- Using RFG
- Contact Information
The Clean Air Act Amendments of 1990 required reformulated gasoline (RFG) to be used in nine major metropolitan areas of the United States with the worst ozone air pollution. In addition, the U.S. Environmental Protection Agency expanded the RFG Program at the request of many state governors to allow areas with a history of ozone problems to voluntarily become part of the program. The RFG Program is federally implemented year-round in these areas as an emission-reduction program to control ozone and air toxic emissions.
RFG is designed to reduce air toxins and emissions of volatile organic compounds by decreasing the amount of toxic compounds, such as benzene, and lowering the evaporation rate of the fuel. The RFG Program began Jan. 1, 1995.
Texas Counties Required to Use RFG
The Houston-Galveston-Brazoria nonattainment area is required by the Clean Air Act Amendments of 1990 to use RFG. This eight-county area includes Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller Counties.
The Dallas–Fort Worth nonattainment area voluntarily opted into the RFG Program. This four-county area includes Collin, Dallas, Denton, and Tarrant Counties.
RFG used in these counties in the summer months may not exceed a Reid vapor pressure (RVP) of 6.8 pounds per square inch (psi). Summertime conventional gasoline in other areas of Texas may have a RVP as high as 8.7 psi. RFG used in these counties in the winter months may have the same RVP as conventional gasoline, which can be as high as 11.5 psi.
The Difference Between Oxygenated Gasoline and RFG
Oxygenated fuel is conventional gasoline that has been blended with an oxygenate to achieve a certain concentration of oxygen in the fuel by weight.
RFG is a formulation of gasoline that has lower amounts of certain chemical compounds that contribute to the formation of ozone and air toxins. It does not evaporate as readily as conventional gasoline during the summer months. It may contain oxygenates, which increase the combustion efficiency of gasoline and reduce carbon monoxide emissions.
The exhaust emissions of vehicles using RFG will have less air toxins and ozone-forming pollutants, and the RFG should have no adverse effects on vehicle performance or the durability of engine and fuel system components. However, there may be a slight decrease in fuel mileage (1–3 percent) due to the higher concentrations of oxygenates.
RFG may be purchased at any gasoline-dispensing facility within the Houston-Galveston-Brazoria and Dallas–Fort Worth nonattainment areas.
For more information about reformulated gasoline, visit the EPA’s Web page on RFG.
For additional information about RFG in Texas, contact
Air Quality Division, TCEQ