21 CFR § 556.283
Florfenicol
June 25, 2020
(a) Acceptable daily intake (ADI). The ADI for total residue of florfenicol is 10 µg/kg of body weight per day.
(b) Tolerances. The tolerances for florfenicol amine (marker residue) are:
(1) Cattle.
(i) Liver (target tissue): 3.7 ppm.
(ii) Muscle: 0.3 ppm.
(2) Swine.
(i) Liver (target tissue): 2.5 ppm.
(ii) Muscle: 0.2 ppm.
(3) Catfish. Muscle (target tissue): 1 ppm.
(4) Freshwater-reared warmwater finfish (other than catfish) and salmonids. Muscle/skin (target tissue): 1 ppm.
(c) Related conditions of use. See §§520.955, 522.955, 522.956, and 558.261 of this chapter.