In 1993, Public Citizen Health Research Group (Public Citizen) (plaintiff) petitioned the Occupational Safety and Health Administration (OSHA) (defendant) to issue an emergency temporary standard for hexavalent chromium. OSHA sets temporary standards without notice-and-comment procedures when it finds that urgent action is needed to protect workers against grave danger. OSHA declined to do so, finding no grave danger, but agreed that the current standard for hexavalent chromium can result in an excess risk of lung cancer. OSHA announced that it would begin rulemaking on this issue. Rulemaking was delayed for many years. One reason was that OSHA decided to wait for a study by Johns Hopkins University that would be the most complete and comprehensive study on the subject. The study was not released until August 2000, and after it was released, OSHA was concerned about the weaknesses in the study. Another reason was that when the George W. Bush administration took office, it ordered that new regulatory actions must be reviewed by an agency head appointed after January 20, 2001. The final reason was that 9/11 and anthrax attacks in the fall of 2001 required OSHA to immediately divert resources elsewhere. Public Citizen petitioned the United State Court of Appeals for the Third Circuit for review alleging that the delay had been unreasonable and asking the court to compel agency action under the Administrative Procedure Act, 5 U.S.C. § 706(1).