21 CFR § 510.105 - Labeling of drugs for use in milk-producing animals.
(a) Part 526 of this chapter provides for new animal drugs intended for intramammary use in animals and includes conditions of use intended to prevent the contamination of milk from the use of such drugs.
(b) Preparations containing antibiotics and other potent drugs labeled with directions for use in milk-producing animals will be misbranded under section 502(f)(2) of the act unless their labeling bears appropriate warnings and directions for use to avoid adulteration of milk under section 402(a)(2)(c)(ii) of the act.
(c) It is the position of the Food and Drug Administration that the labeling for such preparations should bear a clear warning that either:
(1) The article should not be administered to animals producing milk, since to do so would result in contamination of the milk; or
(2) The label should bear the following statement: “Warning: Milk that has been taken from animals during treatment and for __ hours after the latest treatment must not be used for food”, the blank being filled in with the figure that the manufacturer has determined by appropriate investigation is needed to insure that the milk will not carry violative residues resulting from use of the preparation. If the use of the preparation as recommended does not result in contamination of the milk, neither of the above warning statements is required.