Mo. Rev. Stat. § 305.125: Refusal to submit to test, effect, penalties.

If a person refuses upon the request of the officer to submit to a chemical test under section 577.041, then no test shall be given. Any refusal to submit to a test shall be an infraction which may be punished by a fine of up to one thousand dollars. The officer shall inform the person that his or her failure to submit to the test may result in a fine and administrative penalties by the Federal Aviation Administration.