The American Fuel & Petrochemical Manufacturers filed comments opposing the US Environmental Protection Agency’s (EPA) proposed rule Regulation of Fuels and Fuel Additives: 2013 Renewable Fuel Standard (RFS).

“I have long asserted that the RFS is broken and is harmful to countless parties, but nothing has been done to address the problems it has created,” said AFPM President Charles T. Drevna in a statement.

The trade group claims the EPA has “refused to utilize flexibility” with regard to the mandated volume of ethanol to be blended with gasoline under RFS and “continues to set cellulosic biofuel standards that are divorced from reality.”

AFPM points to studies it says confirm ethanol blends in excess of 10% will damage gasoline engines and fuel delivery infrastructure. Cellulosic ethanol mandates are problematic because the nascent industry does not yet produce the fuel in volumes required to satisfy the mandates.

Interestingly, the AFPM and environmental group Natural Resources Defense Council agree that EPA should tweak the RFS over time in response to changing market conditions, supply/demand fundamentals and environmental trends, even if they differ on exactly what tweaks should be made.

“The Energy Independence and Security Act of 2007 (EISA) provides EPA tools to adjust the volumes of renewable fuels in response to market conditions and amid an environment of declining gasoline demand,” the AFPM said in a statement.

“As EPA administers the RFS, it must continuously monitor and optimize the program. It must make good on its public commitment to periodically refine and reevaluate its feedstock assessments as biofuel volumes, agricultural markets and environmental trends evolve over time, the NRDC’s Brian Sui recently wrote on their staff blog SWiTCHBOARD.

But that’s where agreement between the groups on this issue ends, with the AFPM calling “upon EPA to utilize its existing authority to waive the RFS requirements in the face of these technological realities,” and NRDC proclaiming “For now, EPA should be commended for its hard work and willingness to separate the good from the risky. We hope that this work will continue as we chart a course for globally sustainable biofuels one step at a time.”