Mo. Rev. Stat. § 292.570: Penalty.

Any person, firm or corporation engaged in the manufacture or sale of the articles herein mentioned who shall violate or who shall fail to comply with the provisions of sections 292.550 to 292.570, shall be deemed guilty of a misdemeanor, and on conviction, shall be punished by a fine of not less than ten nor more than fifty dollars, or by imprisonment in the county jail for a period of not more than ten days, or by both such fine and imprisonment.