• While FDA’s Center for Veterinary Medicine (CVM) accepts that absolute avoidance of all batch-to-batch drug carryover may not be possible in the production of animal feed, CVM’s “Current Good Manufacturing Practice for Medicated Feeds” regulations require the establishment of equipment cleanout procedures that are adequate to avoid unsafe contamination of animal feeds with drugs.  “Unsafe” contamination of an animal feed refers to a degree of contamination, by a drug approved for a medicated feed use, that poses an unacceptable risk to human health (from consumption of milk, meat, or eggs containing drug residue) or animal health (for example, horses consuming feed contaminated with ionophore drugs like monensin can result in severe illness or death).

• On January 30, 2023, FDA published notice of the availability of a final guidance for industry that provides information on some ways to comply with the CGMP requirements at 21 CFR §§ 225.65 and 225.165 to help prevent unsafe contamination of animal feed from drug carryover.  Guidance for Industry #272, titled, “Practices to Prevent Unsafe Contamination of Animal Feed from Drug Carryover,” contains details and factors to consider in designing cleanout practices to protect the health of the animals consuming the animal feed and, in the case of food-producing animals, protect human health from unsafe contamination of animal feed from drug carryover.  Factors outlined for consideration in developing physical cleanout, flushing, and sequencing procedures include:

  • risks to human and/or animal health;

  • types of animal feed that are manufactured (such as medicated requiring a license);

  • animal species consuming the feed;

  • production stages of the animals;

  • the drugs being used and their levels; and

  • the types of equipment used in the facility.

The guidance also notes that alternative, equally effective practices other than physical cleanout, flushing, and sequencing are permitted to prevent unsafe contamination of animal feed from drug carryover. 

• FDA has concurrently withdrawn Compliance Policy Guides Sec. 680.500 “Unsafe Contamination of Animal Feed from Drug Carryover” and 680.600 “Sequencing as a Means to Prevent Unsafe Drug Contamination in the Production, Storage, and Distribution of Feeds” because the new guidance, #272, contains much of the information found in the older CPGs as well as updates and additional information.