Section 556.168 - Coumaphos(b)Tolerances. The tolerances for coumaphos (measured as coumaphos and its oxygen analog, O,O-diethyl O-3- chloro-4-methyl-2-oxo-2 H-1- benzopyran-7-yl phosphate) are: (1)Chickens.(i) Edible tissues (excluding eggs): 1 ppm.(c)Related conditions of use. See § 558.185 of this chapter.86 FR 14821, Mar. 19, 2021 84 FR 32993, 9/9/2019; 85 FR 18121, 4/1/2020; 86 FR 14821, 3/19/2021