On March 2, a bipartisan group of Senators, led by Senator Deb Fischer (R-NE), reintroduced the Consumer and Fuel Retailer Choice Act (S. 517), which would amend the Clean Air Act to allow for the year-round sale of mid-level ethanol blends, particularly E15.

The 1990 Clean Air Act Amendments require refiners to control for smog-forming compounds in gasoline. Commonly referred to as smog, ozone is a complex mixture formed when air pollutants react with each other in the presence of sunlight. Ground-level ozone impairs lung functioning and contributes to increased incidences of asthma and other lung diseases, especially among children and the elderly. A hazy summer day, often referred to as a “bad air day” is the result of ozone formation. Over time, ozone exposure is linked to serious health impacts.

The warmer the ambient temperature, the more quickly gasoline vaporizes to form dangerous smog-forming compounds. To reduce the formation of ozone in summer months, the EPA regulates the volatility of gasoline.  Refiners accomplish this by changing the fuel blend in anticipation of the warmer season, to the aptly named summer blends. EPA requires retail gasoline stations to offer summer blends between June 1 and September 15.

Reid Vapor Pressure (RVP) is a measure of gasoline volatility, or its ability to vaporize. Each component of gasoline adds to the overall RVP of a gasoline blend, and certain blending components have a higher RVP rating than others. To cut smog levels, EPA requires that summer blends have an RVP cap of no more than 9 pounds per square inch (psi). In some National Ambient Air Quality non-attainment areas, the cap is as low as 7.8 psi. Additionally, EPA allows states to require stricter standards (as low as 7.0 psi) in regions with poorer air quality. Refiners accomplish the various summertime RVP targets by using different proportions of the various gasoline components than they do in the wintertime.  

Currently, about 95 percent of U.S. gasoline is sold as E10 (10 percent ethanol, 90 percent gasoline). Adding 10 percent ethanol to gasoline raises gasoline’s RVP rating by one psi, to approximately 10 psi, according to the National Renewable Energy Lab. Because of this phenomenon, the EPA granted E10 a one psi waiver (commonly referred to as the one-pound waiver) in 1992. Currently, higher blends of ethanol, such as E15, do not have a waiver. While neat ethanol actually has a very low RVP rating (2 psi), the chemical interaction between small volumes of ethanol and gasoline causes RVP to increase.  As the volume of ethanol in the fuel is increased beyond 10 percent, this effect is erased, and the RVP of the gasoline begins to drop. 

The Senate bill would lift the RVP cap, allowing for the year-round sale of E15, with Senator Fischer (R-NE) stating, “The EPA should be consistent in the way it treats different fuel blends as a matter of fairness and to give consumers more options for fueling their vehicles. The EPA has never acted on its authority to grant a Reid vapor pressure waiver for E15. This bill proposes a legislative fix to fill the void.”  Lifting the RVP cap has been widely supported by ethanol trade groups; independent fuel retailers in upping the offering of E15 at gas stations; and the Governors of Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota and South Dakota.  There has been disagreement between ethanol trade groups as to whether EPA can address the RVP waiver, or if an act of Congress is required.

Earlier this week, it was speculated that the White House would be releasing an Executive Order to move the point of obligation from fuel refiners to blenders, in exchange for lifting the RVP cap and other biofuels tax credits. While the White House has denied such allegations, special regulatory advisor Carl Icahn and EPA Administrator Scott Pruitt (and former Oklahoma Attorney General) have raised the potential of moving the point of obligation.


For more information see: 

Bipartisan Senators Seek to Expand Market for Biofuels, Senator Fischer 

Summertime, When the Living’s Easy, EESI 

7 governors ask EPA to remove RVP limit on E15, Ethanol Producer Magazine