Mo. Rev. Stat. § 302.275
Any employer of a person licensed pursuant to section 302.272 to operate a school bus, as that term is defined in section 301.010, shall notify the director of the department of revenue within ten days of discovering that the person has failed to pass any drug, alcohol or chemical test administered pursuant to the requirements of any federal or state law, rule or regulation regarding the operation of a school bus. The notification shall consist of the person's name and any other relevant information required by the director. The director shall determine the manner in which the notification is made. Any employer, or any officer of an employer, who knowingly fails to comply with the notification requirement of this section or who knowingly provides a false notification shall be guilty of an infraction.
§ 302.275, RSMo