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United States • Title 21 CFR • Part 500

Part 500PART 500—GENERAL

Part 500 outlines general provisions for animal drugs, feeds, and related products regulated by the FDA. It addresses specific substances like anthelmintics, timed-release drugs, methylene blue, gentian violet, PCBs, and hexachlorophene, detailing their regulatory status, labeling requirements, and conditions for use. It also references other parts of the CFR for specific manufacturing and processing controls.

What this part covers

  • Specifies requirements for thermally processed low-acid foods for animals, referencing parts 507 and 113.
  • Outlines emergency permit control for thermally processed low-acid foods for animals, referencing part 108.
  • Mandates specific labeling for anthelmintic drugs, requiring consultation with a veterinarian for parasitism diagnosis and treatment.
  • Classifies timed-release dosage form animal drugs as new animal drugs, requiring approved applications or index listings and data on release rates and safety.
  • Reclassifies methylene blue-containing drugs for oral use in cats or dogs as new animal drugs due to safety and efficacy concerns.
  • Determines gentian violet is a food additive or new animal drug, not generally recognized as safe for animal feed or effective for veterinary use in food animals.
  • Imposes restrictions on the use of Polychlorinated Biphenyls (PCBs) in animal feed production, handling, and storage to prevent contamination.
  • Defines the regulatory status of hexachlorophene in animal drugs, requiring NADAs for uses beyond topical preservatives on non-food-producing animals.
  • Identifies propylene glycol in cat food as a food additive not generally recognized as safe.
  • Addresses misbranding of animal drugs due to inadequate labeling.

Sections in Part 500

§ 500.1410

N-methyl-2-pyrrolidone.

Standard for residues.n(a) No residues of -methyl-2-pyrrolidone may be found in the uncooked edible tissues of cattle and swine as determined by methods in paragraph (b) of this section. Incorporation by reference.https://www.fda.gov/about-fda/center-veterinary-medicine/cvm-foia-electronic-reading-room.fr.inspection@nara.gov,www.archives.gov/federal-register/cfr/ibr-locations.html.(b) The standards required in this section are incorporated by reference into this section with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. All approved material is available for inspection at the Food and Drug Administration's Dockets Management Staff (HFA-305), 5630 Fishers Lane, Rm. 1061, Rockville, MD 20852, 240-402-7500, between 9 a.m. and 4 p.m., Monday through Friday. It may be obtained from the sources indicated elsewhere in paragraph (b) of this section and at: It is also available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email or go to: (1) Food and Drug Administration, Center for Veterinary Medicine, 7500 Standish Pl., Rockville, MD 20855,…

§ 500.23

Thermally processed low-acid foods packaged in hermetically sealed containers.

Except as provided in § 507.5(b) of this chapter, the provisions of parts 507 and 113 of this chapter apply to the manufacturing, processing, or packing of low-acid foods in hermetically sealed containers, and intended for use as food for animals. [80 FR 56337, Sept. 17, 2015]

§ 500.24

Emergency permit control.

The provisions of part 108 of this chapter shall apply to the issuance of emergency control permits for the manufacturer or packer of thermally processed low-acid foods packaged in hermetically sealed containers, and intended for use as food for animals. [61 FR 37681, July 19, 1996]

§ 500.25

Anthelmintic drugs for use in animals.

(a) The Commissioner of Food and Drugs has determined that, in order to assure that anthelmintic drugs, including animal feeds bearing or containing such drugs, which do not carry the prescription statement are labeled to provide adequate directions for their effective use, labeling of these anthelmintic drugs shall bear, in addition to other required information, a statement that a veterinarian should be consulted for assistance in the diagnosis, treatment, and control of parasitism. (b) The label and any labeling furnishing or purporting to furnish directions for use, shall bear conspicuously the following statement: “Consult your veterinarian for assistance in the diagnosis, treatment, and control of parasitism.” (c) For drugs covered by approved new animal drug applications, the labeling revisions required for compliance with this section may be placed into effect without prior approval, as provided for in § 514.8(c)(3) of this chapter. For drugs listed in the index, the labeling revisions required for compliance with this section may be placed into effect without prior granting of a request for a modification, as provided for in § 516.161(b)(1) of this chapter. (d)…

§ 500.26

Timed-release dosage form drugs.

(a) Drugs are being offered in dosage forms that are designed to release the active ingredients over a prolonged period of time. There is a possibility of unsafe overdosage or ineffective dosage if such products are improperly made and the active ingredients are released at one time, over too short or too long a period of time, or not released at all. Drugs marketed in this form, which are referred to by such terms as timed-release, controlled-release, prolonged-release, sustained-release, or delayed-release drugs, are regarded as new animal drugs within the meaning of section 201(v) of the Federal Food, Drug, and Cosmetic Act. (b) Timed-release dosage form animal drugs that are introduced into interstate commerce are deemed to be adulterated within the meaning of section 501(a)(5) of the act and subject to regulatory action, unless such animal drug is the subject of an approved new animal drug application, or listed in the index, as required by paragraph (a) of this section. (c) The fact that the labeling of this kind of drug may claim delayed, prolonged, controlled, or sustained-release of all or only some of the active ingredients does not affect the new animal drug status of…

§ 500.27

Methylene blue-containing drugs for use in animals.

(a) New information requires a re- evaluation of the status of drugs containing methylene blue (tetramethylthionine chloride) for oral use in cats or dogs. (1)(i) It has been demonstrated that two orally administered urinary antiseptic-antispasmodic preparations that contained methylene blue cause Heinz body hemolytic anemia in cats when used according to label directions. The specific cause of the reaction was determined to be the methylene blue contained in the preparations. The reaction can be severe enough to cause death of treated animals. (ii) The Heinz body hemolytic anemia reaction to methylene blue has also been demonstrated in dogs under laboratory conditions. The precise mechanism by which methylene blue produces the characteristic erythrocytic inclusion bodies (Heinz bodies) and associated hemolytic anemia is unclear. (2) The effectiveness of orally administered methylene blue as a urinary antiseptic is open to question. It appears that following oral administration, methylene blue is poorly and erratically absorbed and also slowly and erratically excreted in the urine. Studies in the dog indicate it is excreted in the urine essentially as leukomethylene blue…

§ 500.29

Gentian violet for use in animal feed.

The Food and Drug Administration has determined that gentian violet is not generally recognized as safe for use in animal feed and is a food additive subject to section 409 of the Federal Food, Drug, and Cosmetic Act (the act), unless it is intended for use as a new animal drug, in which case it is subject to section 512 of the act. The Food and Drug Administration has determined that gentian violet is not prior sanctioned for any use in animal feed. [56 FR 40506, Aug. 15, 1991]

§ 500.30

Gentian violet for animal drug use.

The Food and Drug Administration (FDA) has determined that gentian violet is not generally recognized as safe and effective for any veterinary drug use in food animals and is a new animal drug subject to section 512 of the Federal Food, Drug, and Cosmetic Act. FDA has determined that gentian violet is not exempted from new animal drug status under the “grandfather” provisions of the Drug Amendments of 1962 (21 U.S.C. 342). [56 FR 40507, Aug. 15, 1991]

§ 500.45

Use of polychlorinated biphenyls (PCB's) in the production, handling, and storage of animal feed.

closed systems,(a) Polychlorinated biphenyls (PCB's) represent a class of toxic industrial chemicals manufactured and sold under a variety of trade names, including: Aroclor (United States); Phenoclor (France); Colphen (Germany); and Kanaclor (Japan). PCB's are highly stable, heat resistant, and nonflammable chemicals. Industrial uses of PCB's include, or did include in the past, their use as electrical transformer and capacitor fluids, heat transfer fluids, hydraulic fluids, plasticizers, and in formulations of lubricants, coatings, and inks. Their unique physical and chemical properties and widespread, uncontrolled industrial applications have caused PCB's to be a persistent and ubiquitous contaminant in the environment, causing the contamination of certain foods. In addition, incidents have occurred in which PCB's have directly contaminated animal feeds as a result of industrial accidents (leakage or spillage of PCB fluids from plant equipment). These accidents in turn cause the contamination of food intended for human consumption (meat, milk, and eggs). Investigations by the Food and Drug Administration have revealed that heat exchange fluids for certain pasteurization…

§ 500.46

Hexachlorophene in animal drugs.

(a) The Commissioner of Food and Drugs has determined that there are no adequate data to establish that animal drugs containing hexachlorophene are safe and effective for any animal use other than in topical products for use on non-food-producing animals as part of a product preservative system at a level not to exceed 0.1 percent; that there is no information on the potential risk to humans from exposure to hexachlorophene by persons who apply animal products containing the drug at levels higher than 0.1 percent; and that there is likewise no information on human exposure to animals on which these animal drugs have been used and no information on possible residues of hexachlorophene in edible products of food-producing animals treated with new animal drugs that contain any quantity of hexachlorophene. (b) Animal drugs containing hexachlorophene for other than preservative use on non-food-producing animals at levels not exceeding 0.1 percent are considered new animal drugs and shall be the subject of new animal drug applications (NADA's). (c) Any person currently marketing animal drugs that contain hexachlorophene other than as part of a product preservative system for products…

§ 500.50

Propylene glycol in or on cat food.

The Food and Drug Administration has determined that propylene glycol in or on cat food is not generally recognized as safe and is a food additive subject to section 409 of the Federal Food, Drug, and Cosmetic Act (the act). The Food and Drug Administration also has determined that this use of propylene glycol is not prior sanctioned. [61 FR 19544, May 2, 1996]

§ 500.51

Labeling of animal drugs; misbranding.

(a) Among the representations on the label or labeling of an animal drug which will render the drug misbranded are any broad statements suggesting or implying that the drug is not safe and effective for use when used in accordance with labeling direction, or suggesting or implying that the labeling does not contain adequate warnings or adequate directions for use. Such statements include, but are not limited to: (1) Any statement that disclaims liability when the drug is used in accordance with directions for use contained on the label or labeling. (2) Any statement that disclaims liability when the drug is used under “abnormal” or “unforeseeable” conditions. (3) Any statement limiting the warranty for the products to a warranty that the drug in the package contains the ingredients listed on the label. (b) This regulation is not intended to prohibit any liability disclaimer that purports to limit the amount of damages or that sets forth the legal theory under which damages are to be recovered. (c) Any person wishing to obtain an evaluation of an animal drug liability disclaimer under this regulation may submit it to Division of Compliance, (HFV-230), Center for Veterinary…

§ 500.52

Use of terms such as “tonic”, “tone”, “toner”, or “conditioner” in the labeling of preparations intended for use in or on animals.

tonic, tone, toner,tonic, tone, toner,(a) The use of terms such as and similar terms in the labeling of a product intended for use in or on animals implies that such product is capable of a therapeutic effect(s) and causes such a product to be a drug within the meaning of section 201(g) of the Federal Food, Drug, and Cosmetic Act. The unqualified use of such terms in a product's labeling fails to provide adequate directions and indications for use of such product and causes it to be misbranded within the meaning of section 502(a) and (f)(1) of the act. The terms and similar terms may be used in labeling only when appropriately qualified so as to fully inform the user regarding the intended use(s) of the product. conditionerconditioner(b) The unqualified use of the term and similar terms in the labeling of a product intended for use in or on animals implies that such product is capable of a therapeutic effect(s) and causes such a product to be a drug within the meaning of section 201(g) of the act. The unqualified use of such terms in a product's labeling fails to provide adequate directions and indications for use of such product and causes it to be misbranded within the meaning…

§ 500.55

Exemption from certain drug-labeling requirements.

(a) Section 201.105(c) of this chapter provides that in the case of certain drugs for which directions, hazards, warnings, and use information are commonly known to practitioners licensed by law, such information may be omitted from the dispensing package. Under this proviso, the Commissioner of Food and Drugs will offer an opinion, upon written request, stating reasonable grounds therefore on a proposal to omit such information from the dispensing package. (b) The Commissioner of Food and Drugs has considered submitted material covering a number of drug products and has offered the opinion that the following drugs when intended for those veterinary uses for which they are now generally employed by the veterinary medical profession, should be exempt from the requirements of § 201.105(c) of this chapter, provided that they meet the conditions prescribed in this paragraph. Preparations that are not in dosage unit form (for example, solutions) will be regarded as meeting the conditions with respect to the maximum quantity of drug per dosage unit if they are prepared in a manner that enables accurate and ready administration of a quantity of drug not in excess of the stated maximum…

§ 500.65

Epinephrine injection 1:1,000 in 10-milliliter containers for emergency treatment of anaphylactoid shock in cattle, horses, sheep, and swine.

(a) Anaphylactoid reactions in cattle, horses, sheep, and swine occur occasionally from the injection of antibiotics, bacterins, and vaccines. Adequate directions for use of these antibiotics, bacterins, and vaccines can generally be written for use by the laity and thus are available to livestock producers. Epinephrine injection is effective for the treatment of anaphylactoid reactions in animals and would be of value in saving lives of animals if it were readily available at the time of administration of the causative agents. In connection with this problem the Food and Drug Administration has obtained the views of the Advisory Committee on Veterinary Medicine, and other experts, and has concluded that adequate directions for over-the-counter sale of epinephrine injection 1:1,000 can be prepared. (b) In view of the above, the Commissioner of Food and Drugs has concluded that it is in the public interest to make epinephrine injection 1:1,000 available for sale without a prescription provided that it is packaged in vials not exceeding 10 milliliters and its label bears, in addition to other required information, the following statements in a prominent and conspicuous manner: “For…

§ 500.80

Scope of this subpart.

(a) The Federal Food, Drug, and Cosmetic Act requires that sponsored compounds intended for use in food-producing animals be shown to be safe and that food produced from animals exposed to these compounds be shown to be safe for consumption by people. The statute prohibits the use in food-producing animals of any compound found to induce cancer when ingested by people or animals unless it can be determined by methods of examination prescribed or approved by the Secretary (a function delegated to the Commissioner of Food and Drugs) that no residue of that compound will be found in the food produced from those animals under conditions of use reasonably certain to be followed in practice. This subpart identifies the steps a sponsor of a compound shall follow to secure the approval of the compound. The requirements of this subpart shall also apply to a request for an import tolerance under § 510.205 of this chapter. FDA guidance documents contain the procedures and protocols FDA recommends for the implementation of this subpart. These guidance documents are available from the Division of Dockets Management (HFA-305), Food and Drug Administration, 5630 Fishers Lane, rm. 1061,…

§ 500.82

Definitions.

(a) The definitions and interpretations contained in section 201 of the act apply to those terms when used in this subpart. (b) The following definitions apply to this subpart: Actet seq. means the Federal Food, Drug, and Cosmetic Act (sections 201-901, 52 Stat. 1040 as amended (21 U.S.C. 301-392)). Essential nutrientsessentialessentialessential means compounds that are found in the tissues of untreated, healthy target animals and not produced in sufficient quantity to support the animal's growth, development, function, or reproduction, e.g., vitamins, minerals, amino acids, and fatty acids. These compounds must be supplied from external sources. FDA means the Food and Drug Administration. Limit of detection (LOD) means the lowest concentration of analyte that can be confirmed by the approved regulatory method. Marker residuem52 means the residue selected for assay whose concentration is in a known relationship to the concentration of the residue of carcinogenic concern in the last tissue to deplete to its S. No residue means the marker residue is below the limit of detection using the approved regulatory method. The “no residue” designation applies only to compounds of…

§ 500.84

Conditions for approval of the sponsored compound.

(a) On the basis of the results of the chronic bioassays and other information, FDA will determine whether any of the substances tested are carcinogenic. (b) If FDA concludes that the results of the bioassays do not establish carcinogenicity, then FDA will not subject the sponsored compound to the remainder of the requirements of this subpart. (c) For each sponsored compound that FDA decides should be regulated as a carcinogen, FDA will either analyze the data from the bioassays using a statistical extrapolation procedure as outlined in paragraph (c)(1) of this section or evaluate an alternate procedure proposed by the sponsor as provided in § 500.90. In either case, paragraphs (c)(2) and (3) of this section apply. o52m52(1) For each substance tested in separate bioassays, FDA will calculate the concentration of the residue of carcinogenic concern that corresponds to a maximum lifetime risk to the test animal of 1 in 1 million. FDA will designate the lowest value obtained as S. Because the total diet is not derived from food-producing animals, FDA will make corrections for food intake. FDA will designate as S the concentration of residue in a specific edible tissue…

§ 500.86

Marker residue and target tissue.

m52(a) For each edible tissue, the sponsor shall measure the depletion of the residue of carcinogenic concern until its concentration is at or below S. m52(b) In one or more edible tissues, the sponsor shall also measure the depletion of one or more potential marker residues until the concentration of the residue of carcinogenic concern is at or below S. m52m52m52m52o52(c) From these data, FDA will select a target tissue and a marker residue and designate the concentration of marker residue (R) that the regulatory method must be capable of measuring in the target tissue. FDA will select R such that the absence of the marker residue in the target tissue above R can be taken as confirmation that the residue of carcinogenic concern does not exceed S in each of the edible tissues and, therefore, that the residue of carcinogenic concern in the diet of people does not exceed S. (d) When a compound is to be used in milk- or egg-producing animals, milk or eggs must be the target tissue in addition to the tissue selected to monitor for residues in the edible carcass.

§ 500.88

Regulatory method.

(a) The sponsor shall submit for evaluation and validation a regulatory method developed to monitor compliance with FDA's operational definition of no residue. m52(b) The regulatory method must be able to confirm the identity of the marker residue in the target tissue at a minimum concentration corresponding to the R. FDA will determine the LOD from the submitted analytical method validation data. Federal Register04(c) FDA will publish in the the complete regulatory method for ascertaining the marker residue in the target tissue in accordance with the provisions of sections 409(c)(3)(A), 512(d)(1)(I), and 721(b)(5)(B) of the act. (d) If the sponsor initially submitted a request for an import tolerance under § 510.205 of this chapter, FDA will make the complete regulatory method for ascertaining the marker residue in the target tissue publicly available pursuant to § 510.207(b) of this chapter. [52 FR 49586, Dec. 31, 1987, as amended at 67 FR 78174, Dec. 23, 2002; 86 FR 52410, Sept. 21, 2021]

§ 500.90

Waiver of requirements.

In response to a petition or on the Commissioner's own initiative, the Commissioner may waive, in whole or in part, the requirements of this subpart except those provided under § 500.88. A petition for this waiver may be filed by any person who would be adversely affected by the application of the requirements to a particular compound. The petition shall explain and document why the requirements from which a waiver is requested are not reasonably applicable to the compound, and set forth clearly the reasons why the alternative procedures will provide the basis for concluding that approval of the compound satisfies the requirements of the anticancer provisions of the act. If the Commissioner determines that waiver of any of the requirements of this subpart is appropriate, the Commissioner will state the basis for that determination in the regulation approving marketing of the sponsored compound.

§ 500.92

Implementation.

(a) This subpart E applies to all new animal drug applications, food additive petitions, color additive petitions, and requests for import tolerances concerning any compound intended for use in food-producing animals (including supplemental applications and amendments to petitions). (b) This subpart E also applies in the following manner to compounds already approved: (1) For those compounds that FDA determines may induce cancer when ingested by man or animals, i.e., suspect carcinogens, §§ 500.80(b), 500.82, and 500.90 apply. (2) For those compounds that FDA determines have been shown to induce cancer when ingested by man or animals, §§ 500.82 through 500.90 apply. [52 FR 49586, Dec. 31, 1987, as amended at 86 FR 52410, Sept. 21, 2021]

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