Environmental groups have sued the U.S. Environmental Protection Agency (EPA) over its alleged failure to review air toxics standards for petroleum refiners as required by sections 112(f)(2) and 112(d)(6) of the Clean Air Act. Air Alliance Houston v. Jackson, No. 12-1607(D.D.C. filed 9/27/12). According to the complaint, EPA must review and revise, if necessary, national emissions standards for hazardous air pollutants every eight years. EPA set standards for petroleum refineries under two subparts, which the agency has not reviewed since promulgating them in 1995 and 2002. Plaintiffs have asked the court to order EPA to complete the required reviews and then revise the standards or determine that revisions are not necessary.