---
kind: "section"
citation: "21 C.F.R. § 520.2520a"
title: "21"
number: "520.2520a"
heading: "Trichlorfon and atropine."
url: "https://uscodex.org/cfr/21/520.2520a"
---

# §520.2520a. Trichlorfon and atropine.

- (a) **Specifications.**
  - (1) **For trichlorfon—** O,O-Dimethyl 2,2,2-trichloro-1-hydroxyethyl phosphonate.
  - (2) **For atropine—** Atropine N.F.
- (b) **Sponsor.** See No. 054771 in [§ 510.600(c)](/cfr/21/510.600.md?p=c) of this chapter.
- (c) **Conditions of use in mice—**
  - (1) **Amount.** Administer 1.67 grams of trichlorfon and 7.7 milligrams of atropine per liter continuously for 7 to 14 days as the sole source of drinking water.
  - (2) **Indications for use.** For the treatment of Syphacia obvelata (pinworm) in laboratory mice.
  - (3) **Limitations.** Federal law restricts this drug to use by or on the order of a licensed veterinarian.

## Notes

### Amendments

[79 FR 28832, May 20, 2014]

### Authority

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

### Source

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

### Amendments

[79 FR 28832, May 20, 2014]