Mo. Rev. Stat. § 167.624

Each school board and charter school governing board shall provide training for all employees of the district or charter school in the administration of cardiopulmonary resuscitation and other lifesaving methods, as they determine best. Such board may consult the department of public safety, the state fire marshal's office, the local fire protection authorities, and others as the board sees fit. Any trained employee shall be held harmless and immune from any civil liability for administering cardiopulmonary resuscitation and other lifesaving methods in good faith and according to standard medical practices.