2.—(1) A veterinary surgeon prescribing or administering a veterinary medicinal product to a food-producing animal under the cascade must specify an appropriate withdrawal period.
(2) The withdrawal period must ensure that, if there is a maximum residue limit specified for the active substance in Table 1 in the Annex to Commission Regulation (EU) No 37/2010, the level of residue of the active substance does not exceed that limit.
(3) In any event, unless the Secretary of State has specified in writing a different withdrawal period for a particular veterinary medicinal product, the withdrawal period (irrespective of whether or not a maximum residue limit is specified in Table 1 in the Annex to Commission Regulation (EU) No 37/2010) must not be less than—
(a)7 days for eggs;
(b)7 days for milk;
(c)28 days for meat from poultry and mammals including fat and offal;
(d)500 degree days(1) for fish meat.
The number of days of the withdrawal period is calculated by dividing 500 by the mean temperature of the water in degrees Celsius.