Missouri Basin Well Service, Inc. (MBI) is an oil and gas well-servicing company based in Belfield, North Dakota. After a fire at an MBI worksite injured an employee and the Occupational Safety and Health Administration conducted an inspection, OSHA issued MBI a citation alleging a violation of the general duty clause of the Occupational Safety and Health Act, 29 U.S.C. § 654(a)(1), for exposing its employees to fire and explosion hazards.