---
kind: "section"
citation: "21 C.F.R. § 520.100"
title: "21"
number: "520.100"
heading: "Amprolium."
url: "https://uscodex.org/cfr/21/520.100"
---

# §520.100. Amprolium.

- (a) **Specifications.**
  - (1) Each milliliter of solution contains 96 milligrams (mg) amprolium (9.6 percent solution).
  - (2) **Each gram of powder contains 200 mg amprolium (20 percent).**
- (b) **Sponsors.** See sponsors in 510.600(c) of this chapter.
  - (1) **Nos.** 016592 and 061133 for use of products described in [paragraph (a)](#a) of this section as in [paragraph (d)](#d) of this section.
  - (2) **Nos.** 051072 and 066104 for use of product described in [paragraph (a)(1)](#a-1) of this section as in [paragraph (d)](#d) of this section.
- (c) **Related tolerances.** See [§ 556.50](/cfr/21/556.50.md) of this chapter.
- (d) **Conditions of use—**
  - (1) **Growing chickens, turkeys, and laying hens.** It is used in drinking water as follows:
    - (i) **Amount.** Administer at the 0.012 percent level in drinking water as soon as coccidiosis is diagnosed and continue for 3 to 5 days (in severe outbreaks, give amprolium at the 0.024 percent level); continue with 0.006 percent amprolium-medicated water for an additional 1 to 2 weeks.
    - (ii) **Indications for use.** For the treatment of coccidiosis.
    - (iii) **Limitations.** Use as the sole source of amprolium.
  - (2) **Calves.** Administer concentrate solution or soluble powder as a drench or in drinking water as follows:
    - (i) **Indications for use and amounts—**
      - (A) **As an aid in the prevention of coccidiosis caused by <I>Eimeria bovis</I> and <I>E.** zurnii, administer 5 mg per kilogram (mg/kg) body weight for 21 days during periods of exposure or when experience indicates that coccidiosis is likely to be a hazard.
      - (B) **As an aid in the treatment of coccidiosis caused by <I>E.** bovis and E. zurnii, administer 10 mg/kg body weight for 5 days.
    - (ii) **Limitations.** Withdraw 24 hours before slaughter. A withdrawal period has not been established for this product in preruminating calves. Do not use in calves to be processed for veal. Use as the sole source of amprolium.

## Notes

### Amendments

[71 FR 56346, Sept. 27, 2006, as amended at 72 FR 60551, Oct. 25, 2007; 73 FR 45611, Aug. 6, 2008; 73 FR 70276, Nov. 20, 2008; 74 FR 10484, Mar. 11, 2009; 76 FR 38554, July 1, 2011; 76 FR 40808, July 12, 2011; 78 FR 23, Jan. 2, 2013; 78 FR 17596, Mar. 22, 2013; 78 FR 57058, Sept. 17, 2013; 81 FR 22523, Apr. 18, 2016; 81 FR 59133, Aug. 29, 2016; 84 FR 8972, Mar. 13, 2019; 86 FR 13184, Mar. 8, 2021; 89 FR 85426, Oct. 28, 2024]

### Authority

Authority: 21 U.S.C. 360b.

### Source

Source: 40 FR 13838, Mar. 27, 1975, unless otherwise noted.

### Amendments

[71 FR 56346, Sept. 27, 2006, as amended at 72 FR 60551, Oct. 25, 2007; 73 FR 45611, Aug. 6, 2008; 73 FR 70276, Nov. 20, 2008; 74 FR 10484, Mar. 11, 2009; 76 FR 38554, July 1, 2011; 76 FR 40808, July 12, 2011; 78 FR 23, Jan. 2, 2013; 78 FR 17596, Mar. 22, 2013; 78 FR 57058, Sept. 17, 2013; 81 FR 22523, Apr. 18, 2016; 81 FR 59133, Aug. 29, 2016; 84 FR 8972, Mar. 13, 2019; 86 FR 13184, Mar. 8, 2021; 89 FR 85426, Oct. 28, 2024]