(a) Contracts. - A person under contract with a department, agency, or instrumentality of the United States Government that transports or causes to be transported hazardous material, or manufactures, fabricates, marks, maintains, reconditions, repairs, or tests a packaging or a container that the person represents, marks, certifies, or sells as qualified for use in transporting hazardous material must comply with this chapter, regulations prescribed and orders issued under this chapter, and all other requirements of the Government, State and local governments, and Indian tribes (except a requirement preempted by a law of the United States) in the same way and to the same extent that any person engaging in that transportation, manufacturing, fabricating, marking, maintenance, reconditioning, repairing, or testing that is in or affects commerce must comply with the provision, regulation, order, or requirement. (b) Nonapplication. - This chapter does not apply to - (1) a pipeline subject to regulation under chapter 601 of this title; or (2) any matter that is subject to the postal laws and regulations of the United States under this chapter or title 18 or 39.