The Toxic Substances Control Act regulates the use of polychlorinated biphenyls (PCBs) and grants the Environmental Protection Agency (EPA) (defendant) the authority to promulgate regulations related to the use of PCBs. Under this authority, the EPA promulgated regulations regarding the disposal of PCBs. The regulations permitted parties to use alternative methods of disposal of PCBs other than the methods provided for by the regulations as long the alternative methods did not pose an unreasonable risk to health or the environment. The EPA created a guidance document governing two regulations related to alternative methods for disposal of PCBs. The guidance document was not subject to a public-notice-and-comment period. The guidance document appears to provide binding instruction on how to perform the risk assessment for alternative disposal methods in one of two ways put forth by the EPA. The document does not leave the option open for affected parties to use a third method for risk assessment. General Electric Co. (GE) (plaintiff) petitioned the lower court for review of the guidance document because it was promulgated without following Administrative Procedure Act (APA) procedures for promulgation of a legislative rule. The petition was denied, and GE appealed to the United States Court of Appeals for the District of Columbia Circuit.