Volatility is the property of a liquid fuel that defines its evaporation characteristics. RVP is an abbreviation for “Reid vapor pressure,” a common measure of gasoline volatility, as well as a generic term for gasoline volatility. EPA regulates the vapor pressure of all gasoline during the summer months (June 1 to September 15 at retail stations).
Volatility Regulations for Gasoline and Alcohol Blends. EPA established a two-phase reduction in summertime commercial gasoline volatility. These rules reduce gasoline emissions of volatile organic compounds (VOC) that are a major contributor to ground-level ozone (smog). Phase I was applicable to calendar years 1989 through 1991. Depending on the state and month, gasoline RVP was not to exceed 10.5 psi (pounds per square inch), 9.5 psi, or 9.0 psi. Phase II is applicable to 1992 and later calendar years. Depending on the state and month, gasoline RVP may not exceed 9.0 psi or 7.8 psi. See EPA Guide to Federal and State RVP Standards. EPA provides a 1.0 psi RVP allowance for gasoline containing ethanol at 9 to 10 volume percent.
- Final Rule: Volatility Regulations for Gasoline and Alcohol Blends Sold in Calendar Years 1992 and Beyond. 55 FR 23658, June 11, 1990 (electronic version not available).
- Final Rule: Volatility Regulations for Gasoline and Alcohol Blends Sold in Calendar Years 1989 and Beyond. 54 FR 11868,March 22, 1989 (electronic version not available).
Proposed Relaxation of Summer Gasoline Volatility Standard for Denver/Boulder Area. EPA proposed to change the federal volatility (RVP) standard applicable to summer gasoline supplied to the Denver/Boulder area from 7.8 pounds per square inch (psi) to 9.0 psi. This rule was not finalized due to air quality concerns.