Mo. Rev. Stat. § 292.020
The belting, shafting, machines, machinery, gearing and drums in all manufacturing, mechanical and other establishments in this state, when so placed as to be dangerous to persons employed therein or thereabout while engaged in their ordinary duties, shall be safely and securely guarded when possible; if not possible, then notice of its danger shall be conspicuously posted in such establishments. Whenever the director of the inspection section, or his assistant, or deputy, finds that guards have not been installed or notice of danger posted, as required by the provisions of this section, he shall at once, in writing, order the owner or owners, or the person or persons in charge of the machinery, plant, establishment, or place, to make the alterations, additions, or repairs necessary within ten days; and if the said alterations, additions or repairs be not made within ten days from the date of such order, then such failure to make such alterations shall be deemed a violation of sections 292.010 to 292.250, and in addition to the penalties herein prescribed for such violations, the director or his assistant or deputy, shall be and is hereby empowered to, and he shall seal said defective appliance or appliances in such a manner as to render the same inoperative until said order of the director has been complied with.
§ 292.020, RSMo
RSMo 1939 § 10182