21 CFR 1316.05 : Food And Drugs (§ 1.1 To Parts 1403-1499) — (§ 1300.01 To Parts 1403-1499) — Drug Enforcement Administration, Department Of Justice (§ 1300.01 To Parts 1322-1399) — Administrative Functions, Practices, And Procedures (§ 1316.01 To § 1316.68) — Administrative Inspections (§ 1316.01 To § 1316.13) — Entry.

An inspection shall be carried out by an inspector. Any such inspector, upon (a) stating his purpose and (b) presenting to the owner, operator or agent in charge of the premises to be inspected (1) appropriate credentials, and (2) written notice of his inspection authority under § 1316.06 of this chapter, and (c) receiving informed consent under § 1316.08 or through the use of administrative warrant issued under §§ 1316.09-1316.13, shall have the right to enter such premises and conduct inspections at reasonable times and in a reasonable manner.