Mo. Rev. Stat. § 292.210: Violation a misdemeanor — fines.

Any person or persons, firm or corporation, being the owner, agent, lessee or occupant of any manufacturing, mechanical, mercantile, or other establishment, business or calling in this state to which sections 292.010 to 292.250 apply, or any employee therein or thereat, who shall violate, or aid or abet in violating, any of the provisions of sections 292.010 to 292.250, shall be deemed guilty of a misdemeanor, and, upon conviction in any court of competent jurisdiction in this state, be fined for the first offense not less than twenty-five dollars nor more than two hundred dollars, and for each subsequent offense, not less than one hundred dollars nor more than five hundred dollars, and, in default of payment of such fine and costs, shall be committed to the common jail of the county or city in which the offense was committed until such fine and costs are fully paid.