When EPA waived the RVP requirements in some areas, why did EPA also waive the requirement that gasoline be blended with 10% ethanol to receive the additional 1.0 pound per square inch (psi)?
When ethanol is blended with gasoline (an “alcohol blend”), it tends to increase the RVP of the alcohol-blended gasoline. Therefore, the EPA regulations include a special provision for alcohol blends, in 40 C.F.R. § 80.27(d), to allow up to an additional 1.psi above the applicable RVP standard. The special provision for alcohol blends only applies if the total amount of ethanol is between 9% and 10% of the gasoline. Under an RVP waiver, gasoline without ethanol may be mixed with gasoline blended with ethanol. In such cases, the amount of ethanol in the resulting mixture would be less than the required 9% minimum, and would not qualify for the additional 1.0 psi allowance for alcohol blends provided by 40 C.F.R. § 80.27(d). Therefore, EPA also waived the requirement that gasoline must have between 9% and 10% ethanol to qualify for the additional 1 psi allowed by 40 C.F.R. § 80.27(d) in order to allow gasoline without ethanol to be mixed with gasoline blended with ethanol. The additional
