21 CFR § 556.240
Estradiol and related esters
June 25, 2020
(a) [Reserved]
(b) Residues. Residues of estradiol are not permitted in excess of the following increments above the concentrations of estradiol naturally present in untreated animals:
(1) Cattle.
(i) Muscle: 120 ppt.
(ii) Fat: 480 ppt.
(iii) Kidney: 360 ppt.
(iv) Liver: 240 ppt.
(2) [Reserved]
(c) Related conditions of use. See §§522.840, 522.842, 522.850, 522.1940, 522.2477, and 522.2478 of this chapter.