The U.S. Food and Drug Administration has issued a draft guidance to help animal drug sponsors determine an acute reference dose (ARfD), which is the estimate of the amount of residues expressed on a body weight basis that can be ingested in a period of no more than 24 hours or less without adverse effects or harm to the health of the human consumer. Draft GFI #232, “Studies to Evaluate the Safety of Residues of Veterinary Drugs in Human Food: General Approach to Establish an Acute Reference Dose (ARfD)” outlines the nature and types of data that can be useful in determining an ARfD, the studies that may generate such data, and how the ARfD may be calculated based on these data.

The safety of residues of veterinary drugs in human food is most commonly determined through toxicology studies with the aim to establish an acceptable daily intake (ADI) that represents the amount of a drug that can be safely consumed by a person on a daily basis for a lifetime. In cases where the ADI may not be the appropriate value because some veterinary drug residues may cause acute adverse effects in the human consumer following a single meal, determining the ARfD may be an appropriate approach to address this concern. The ARfD approach has been developed to provide a human health guidance value for pesticides and other chemicals, including veterinary drugs, when their use can result in residues high enough to cause adverse effects following acute or short-term exposures in people consuming large portions of food containing the residue. This contrasts with the use of ADIs, which are established to address potential adverse effects following chronic or long-term exposures to residues in foods.

GFI #232 supports FDA’s work with the International Cooperation on Harmonization of Technical Requirements for Registrations of Veterinary Medicinal Products (VICH), a trilateral (EU-Japan-USA) program aimed at harmonizing technical requirements for veterinary product registration.

The FDA is accepting public comments on this draft guidance beginning on June 1, 2015. To submit your comments electronically to the docket, go to and type docket number FDA-2015-D-1804 in the search box. Please note that the docket will not be open to accept comments until this date. The comment period will close 60 days after it publishes in the Federal Register. While comments are welcome at any time, you should submit them by the closing date for the FDA to consider your comments in drafting the final guidance.

To submit your comments to the docket by mail, use the following address. Be sure to include docket number FDA-2015-D-1804 on each page of your written comments.

Division of Dockets Management
Food and Drug Administration
5630 Fishers Lane, Room 1061
Rockville, MD 20852