StacksVerified U.S. regulatory reference

21 CFR §520.2520a

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)Specifications.
    1. (1)For trichlorfon: O,O-Dimethyl 2,2,2-trichloro-1-hydroxyethyl phosphonate.
    2. (2)For atropine: Atropine N.F.
  2. (b)Sponsor. See No. 054771 in § 510.600(c) of this chapter.
  3. (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.
    1. (2)Indications for use. For the treatment of Syphacia obvelata (pinworm) in laboratory mice.
    2. (3)Limitations. Federal law restricts this drug to use by or on the order of a licensed veterinarian.