49 C.F.R. § 9.1
(b) The purposes of this part are to:
(c) Agency counsel, in his or her discretion, may permit an exception from any requirement in this part. The exception may be granted only when the deviation will not interfere with matters of operational or military necessity, and when agency counsel determines that:
(3) The exception is in the best interest of the Department or the United States.
For Office of Inspector General employees and documents, the Inspector General, in conjunction with the General Counsel of the Department, may permit an exception from any requirement of this part if the Inspector General determines, based on the Inspector General Act of 1978, as amended, that application of the requirement would be inappropriate.