{"data":{"id":"us/21-cfr-556.540","jurisdiction":"us","citation":"21 CFR 556.540","heading":"Progesterone.","body":"(a) [Reserved]\n(b) Residues. Residues of progesterone are not permitted in excess of the following increments above the concentrations of progesterone naturally present in untreated animals:\n(1) Cattle and sheep. (i) Muscle: 5 ppb.\n(ii) Liver: 15 ppb.\n(iii) Kidney: 30 ppb.\n(iv) Fat: 30 ppb.\n(2) [Reserved]\n(c) Related conditions of use. See §§ 522.1940 and 529.1940 of this chapter.","path":["Title 21—Food and Drugs","CHAPTER I—FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES","SUBCHAPTER E—ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS","PART 556—TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD","Subpart B—Specific Tolerances for Residues of Approved and Conditionally Approved New Animal Drugs"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-21.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:47Z","sha256":"7dbce32044d027a91266a58e9f2005b78e4883c258db5b54de9f8273c48908ee","source_id":"us-cfr","stale":true,"prev":"us/21-cfr-556.530","next":"us/21-cfr-556.560"},"notice":"GroundRules: Original legal text. Not legal advice."}