Missouri Revised Statutes Title XXXVIII. Crimes and Punishment; Peace Officers and Public Defenders § 577.031. Persons administering tests not liable, when

No person who administers any test pursuant to the provisions of sections 577.020 to 577.041 upon the request of a law enforcement officer, no hospital in or with which such person is employed or is otherwise associated or in which such test is administered, and no other person, firm, or corporation by whom or with which such person is employed or is in any way associated, shall be civilly liable in damages to the person tested unless for gross negligence, willful or wanton act, or omission.