21 CFR 556.540 - Progesterone.
(b) Tolerances. Residues of progesterone are not permitted in excess of the following increments above the concentrations of progesterone naturally present in untreated animals:
(1) Cattle and sheep - (i) Muscle: 5 parts per billion (ppb).
(ii) Liver: 15 ppb.
(iii) Kidney: 30 ppb.
(iv) Fat: 30 ppb.
(c) Related conditions of use. See §§ 522.1940 and 529.1940 of this chapter.