21 C.F.R. § 556.240 – Estradiol and related esters.

(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. (1) Cattle.
  1. (i) Muscle: 0.2 ppb.
  2. (ii) Liver: 0.6 ppb.
  3. (iii) Kidney: 1.2 ppb.
  4. (iv) Fat: 1.2 ppb.
2. (2) [Reserved]
(c) Related conditions of use. See §§ 522.840, 522.850, 522.1940, 522.2343, 522.2477, and 522.2478 of this chapter.

[84 FR 32993, July 11, 2019, as amended at 87 FR 17947, Mar. 29, 2022]