WASHINGTON ?" Nine energy, food and retail industry groups filed a federal court challenge last week to the Environmental Protection Agency??s (EPA) decision to allow refiners to increase ethanol use to 15 percent in vehicles manufactured between 2001 and 2006, the Washington Examiner reports.

The suit claims the EPA lacks statutory authority and that the move places businesses and consumers at risk.

Last Friday??s filing supplements an earlier challenge to the EPA??s ruling to allow E15 to be used in vehicles manufactured after 2007.

"The EPA??s decision improperly authorizes an increase in ethanol content of gasoline from 10 percent to 15 percent," said the American Petroleum Institute??s Director of Downstream Operations Bob Greco. "EPA's second E15 waiver was based on just as shaky - if not shakier - legal and technical grounds than the first waiver decision."

Tests have uncovered potential compatibility issues with E15 fuel, including the ability for engines to accommodate the higher ethanol mixture and the ability of station pumps and underground storage tanks to handle it.