21 CFR § 556.226 - Enrofloxacin.

---
identifier: "/us/cfr/t21/s556.226"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 556.226 - Enrofloxacin."
title_number: 21
title_name: "Food and Drugs"
section_number: "556.226"
section_name: "Enrofloxacin."
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"
---


# 556.226 Enrofloxacin.

(a) *Acceptable daily intake (ADI).* The ADI for total residue of enrofloxacin is 3 µg/kg of body weight per day.

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

(1) *Cattle.* Liver (target tissue): 0.1 ppm desethylene ciprofloxacin (marker residue).

(2) *Swine.* Liver (target tissue): 0.5 ppm enrofloxacin (marker residue).

(c) *Related conditions of use.* See §§ 516.812 and 522.812 of this chapter.

[84 FR 32993, July 11, 2019, as amended at 86 FR 13188, Mar. 8, 2021]