21 CFR § 556.275 - Fenbendazole.

---
identifier: "/us/cfr/t21/s556.275"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 556.275 - Fenbendazole."
title_number: 21
title_name: "Food and Drugs"
section_number: "556.275"
section_name: "Fenbendazole."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "E"
subchapter_name: "ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS"
part_number: "556"
part_name: "TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "21 U.S.C. 342, 360b, 371."
regulatory_source: "84 FR 32993, July 11, 2019, unless otherwise noted."
cfr_part: "556"
---


# 556.275 Fenbendazole.

(a) *Acceptable daily intake (ADI).* The ADI for total residue of fenbendazole is 40 µg/kg of body weight per day.

(b) *Tolerances.* The tolerances for fenbendazole are:

(1) *Cattle.* (i) Liver (target tissue): 0.8 ppm fenbendazole (marker residue).

(ii) Milk: 0.22 ppm fenbendazole sulfoxide (marker residue).

(2) *Chickens.* (i) Liver (target tissue): 5.2 ppm fenbendazole sulfone (marker residue).

(ii) Eggs: 1.8 ppm fenbendazole sulfone (marker residue).

(3) *Goats.* (i) Liver (target tissue): 0.8 ppm fenbendazole (marker residue).

(ii) [Reserved]

(4) *Swine.* (i) Liver (target tissue): 3.2 ppm fenbendazole (marker residue).

(ii) [Reserved]

(5) *Turkeys.* (i) Liver (target tissue): 6 ppm fenbendazole sulfone (marker residue).

(ii) [Reserved]

(6) *Quail.* (i) Liver (target tissue): 6 ppm fenbendazole sulfone (marker residue).

(ii) [Reserved]

(c) *Related conditions of use.* See §§ 520.905a, 520.905b, 520.905c, 520.905d, and 558.258 of this chapter.

[84 FR 32993, July 11, 2019, as amended at 86 FR 57998, Oct. 20, 2021; 86 FR 61686, Nov. 8, 2021; 89 FR 85428, Oct. 28, 2024]