Environmental Protection Agency chief Scott Pruitt was sued by a renewable fuel trade group on Tuesday for exempting dozens of oil refineries outside the public eye from having to abide by the Renewable Fuel Standard’s ethanol mandate.

The Advanced Biofuel Association is the first biofuel group to sue Pruitt in the D.C. Circuit Court of Appeals over the exemption process after weeks of warnings by the ethanol industry, other biofuel groups, and both Republican and Democratic members of Congress who say what Pruitt is doing is illegal.