The U.S. Environmental Protection Agency may not meet a December 1 deadline to decide whether to approve an industry request to boost the amount of ethanol that can be blended into gasoline, EPA Administrator Lisa Jackson said on November 9.

The pro-ethanol trade group Growth Energy and 54 ethanol manufacturers petitioned the EPA last March to allow gasoline rated as standard transportation fuel to contain up to 15% ethanol by volume, known as E15. U.S. gasoline is now approved to contain up to 10% ethanol. The group filed the request as an emergency waiver appeal to forego the usual multi-year data gathering and research process associated with such fuel changes. According to agency rules, the appeal required a yea or nay response within six months, but agency officials now say that time frame won’t likely be met.

The head of the EPA said the agency may have to work past the December 1 deadline because it is still reviewing test results on how the higher blend rate would affect engines “across the board,” including cars, trucks, snow mobiles, motor boats and lawnmowers. Pro-ethanol interests have promoted the results of a federal study prepared by the National Renewable Energy Laboratory (NREL) for the U.S. Dept. of Energy in fall 2008 that looked at the effect of blends as high as E15 and E20 and found relatively few problems in newer autos. Small engine and automotive groups say the study, which was more observational in nature and lacked scientific controls, is inconclusive at best, leaves many questions unanswered and is primarily an indicator that much more research on higher ethanol blends in small engines is required.