21 CFR § 558.582 - Sulfamerazine.
---
identifier: "/us/cfr/t21/s558.582"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 558.582 - Sulfamerazine."
title_number: 21
title_name: "Food and Drugs"
section_number: "558.582"
section_name: "Sulfamerazine."
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: "558"
part_name: "NEW ANIMAL DRUGS FOR USE IN ANIMAL FEEDS"
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. 354, 360b, 360ccc, 360ccc-1, 371."
regulatory_source: "40 FR 13959, Mar. 27, 1975, unless otherwise noted."
cfr_part: "558"
---
# 558.582 Sulfamerazine.
(a) *Specifications.* Type A medicated articles containing 99 percent sulfamerazine.
(b) *Sponsor.* See No. 054771 in § 510.600(c) of this chapter.
(c) *Related tolerances.* See § 556.660 of this chapter.
(d) *Special considerations.* (1) Federal law restricts medicated feed containing this veterinary feed directive (VFD) drug to use by or on the order of a licensed veterinarian. See § 558.6 for additional requirements.
(2) The expiration date of VFDs for sulfamerazine medicated feeds must not exceed 6 months from the date of issuance. VFDs for sulfamerazine shall not be refilled.
(e) *Conditions of use.* It is used in fish feed for as follows:
| Sulfamerazinegrams/ton | Combination ingrams/ton | Indications for use | Limitations | Sponsor |
| --- | --- | --- | --- | --- |
| (1) To deliver 10 grams of sulfamerazine per 100 pounds of fish per day | | Rainbow trout, brook trout, and brown trout: For control of furunculosis | Formulate to deliver 10 grams of sulfamerazine per 100 pounds of fish per day. Treat for not more than 14 days. Do not treat within 3 weeks of marketing or stocking in stream open to fishing | 054771 |
| (2) [Reserved] | | | | |
[81 FR 95013, Dec. 27, 2016]