---
kind: "section"
citation: "21 C.F.R. § 556.240"
title: "21"
number: "556.240"
heading: "Estradiol and related esters."
url: "https://uscodex.org/cfr/21/556.240"
---

# §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) **Cattle.**
    - (i) **Muscle—** 0.2 ppb.
    - (ii) **Liver—** 0.6 ppb.
    - (iii) **Kidney—** 1.2 ppb.
    - (iv) **Fat—** 1.2 ppb.
  - (2) [Reserved]
- (c) **Related conditions of use.** See §§ [522.840](/cfr/21/522.840.md), [522.850](/cfr/21/522.850.md), [522.1940](/cfr/21/522.1940.md), [522.2343](/cfr/21/522.2343.md), [522.2477](/cfr/21/522.2477.md), and [522.2478](/cfr/21/522.2478.md) of this chapter.

## Notes

### Amendments

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

### Authority

Authority: 21 U.S.C. 342, 360b, 371.

### Source

Source: 84 FR 32993, July 11, 2019, unless otherwise noted.

### Amendments

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