CFR › Title 21 › Part 556 › §556.56021 CFR §556.560Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy link(a)[Reserved](b)Tolerances. The tolerances for pyrantel are:(1)Swine.(i)Liver and kidney: 10 ppm.(ii)Muscle: 1 ppm.(2)[Reserved](c)Related conditions of use. See §§ 520.2045 and 558.485 of this chapter.