The Environmental Protection Agency has decided to put off until next year a ruling on whether fuel suppliers can increase the amount of ethanol in motorists’ tanks from 10 percent to 15 percent.

Biofuel proponents such as the Renewable Fuels Association criticized the delay, calling it a threat to “the continued evolution of America’s ethanol industry.” Members of Congress also questioned the agency’s inaction.

But the National Corn Growers Association took comfort that EPA had given its “tacit endorsement” of higher ethanol blends, saying it showed the agency’s understanding of the importance of moving to higher blends in the near future.

Several organizations, including the Renewable Fuels Association and the NCGA, had asked the agency to raise the 10 percent limit on how much ethanol can be blended in unleaded gasoline for vehicles with conventional engines. So-called “Flex” vehicles can be driven with blends as high as 85 percent ethanol.

“As we are evaluating your E15 waiver petition, we want to make sure we have all the necessary science to make the right decision, EPA Assistant Administrator Gina McCarthy wrote.

“Although all of the studies have not been completed, our engineering assessment to date indicates that the robust fuel, engine and emission control systems on newer vehicles will likely be able to accommodate higher ethanol blends.”

Proponents of the waiver cite a “blend wall” that currently limits ethanol consumption to about 12 billion gallons per year. U.S. biofuel companies currently produce about 10.5 billion gallons per year. Raising the limit to 15 percent would increase consumption to about 19 billion gallons.

“There is ample evidence that demonstrates E15 should be approved,” said Sen. Charles Grassley of Iowa, the state which has the highest number of ethanol plants in the nation. “The EPA has had months to review the data and make an informed decision to approve higher blends of ethanol than are currently allowed.

“With this delay, the Obama administration is delaying the creation of thousands of new, green jobs and creating even more uncertainty in an economy that could use some good news.”

The Renewable Fuels Standard passed by Congress in 2007 requires that the nation’s fuel supply include a total of 36 billion gallons of ethanol by 2022. At least 15 billion gallons of the total are expected to come from corn-based ethanol.

“Kicking the can down the road further delays the development of advanced biofuels such as cellulosic ethanol and works against congressional intent, because without higher blends of ethanol the law can’t be fully implemented,” said Grassley.

Grassley call on the administration to act on his request prior to President Obama’s jobs summit and implement an intermediate blend of 12 percent ethanol to gasoline.

“In order to avoid paralysis by analysis, EPA should immediately approve intermediate ethanol blends, such as E12,” said Renewable Fuels Association President and CEO Bob Dinneen.

“Allowing for a 20 percent increase in ethanol’s potential share of the market would provide some breathing room for the industry while EPA finishes its testing on E15.

“Additionally, it would represent a good faith gesture that underscores the commitment President Obama has pledged to biofuels.”

Dinneen also expressed concern about EPA’s apparent decision to limit the scope of its waiver research to vehicles model year 2001 and newer.

“The data to date has shown no ill-effects of increased ethanol use in any vehicle, regardless of model year. The RFA encourages EPA to look at the waiver request with the entire range of vehicles in mind or provide detailed, scientific rationale for excluding older model vehicles.”

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