Mo. Rev. Stat. § 196.949
Graded fluid milk or fluid milk products not inspected under state milk inspection may be sold, offered for sale, exposed for sale, and delivered in the state of Missouri, or any municipality thereof, if approved by the state milk board as provided for by regulations adopted by the state milk board; provided that, the graded fluid milk or fluid milk products from other states shall be produced and processed under the supervision of a duly authorized governmental agency operating under the provisions of an ordinance, statute, or regulation substantially equivalent to the regulations promulgated and adopted by the state milk board and enforced with equal effectiveness as determined by an official rating survey, and products meet applicable temperature, bacteriological and composition standards when sampled on arrival at point of retail sale. Nothing in this section shall prohibit the state or local health officer from satisfying himself or herself that the governmental agency having jurisdiction over the production and processing is properly enforcing such provisions.
§ 196.949, RSMo