Iowa Admin. Code r. 21-42.6
42.6(2) Prior to approval of a registration application or approval of a label for pet food which contains additives (including drugs, other special purpose additives, or nonnutritive additives), the distributor may be required to submit evidence to prove the safety and efficacy of the pet food when used according to directions furnished on the label. Satisfactory evidence of the safety and efficacy of a pet food may be: