21 CFR §510.210

1. (a)The Commissioner, on his or her own initiative or on the petition of an interested person, under § 10.25 of this chapter, may revoke an import tolerance if:
   1. (1)Scientific evidence shows an import tolerance to be unsafe; or
   2. (2)Information demonstrates that the use of a new animal drug under actual use conditions results in food being imported into the United States with residues exceeding the import tolerance.
2. (b)The Commissioner will provide public notification under § 510.207(b) that will specify the basis for the decision and will be effective at the time the information is made available to the public.
3. (c)A petition for revocation must be submitted in the form specified in § 10.30 of this chapter.