1. (a) Specifications. Type A medicated articles containing 13.2 or 33.3 percent famphur.
2. (b) Sponsor. See No. 000061 in § 510.600(c) of this chapter.
3. (c) Related tolerances. See § 556.273 of this chapter.
4. (d) Special considerations. Famphur is a cholinesterase inhibitor. Do not use this product in animals simultaneously or within a few days before or after treatment with or exposure to cholinesterase-inhibiting drugs, pesticides, or chemicals.

5. (e) Conditions of use. It is used in cattle feed as follows:

   Famphur amount	Indications for use	Limitations	Sponsor
   (1) To provide 1.1 milligrams per pound (mg/lb) body weight per day	Beef cattle and nonlactating dairy cattle: For control of grubs and as an aid in control of sucking lice	Feed for 30 days. Withdraw from dry dairy cows and heifers 21 days prior to freshening. Withdraw 4 days prior to slaughter	000061
   (2) To provide 2.3 mg/lb body weight per day	Beef cattle and nonlactating dairy cattle: For control of grubs	Feed for 10 days. Withdraw from dry dairy cows and heifers 21 days prior to freshening. Withdraw 4 days prior to slaughter	000061

[84 FR 39185, Aug. 9, 2019, as amended at 87 FR 17947, Mar. 29, 2022]