Mo. Rev. Stat. § 311.325
3. Any person under the age of twenty-one years who purchases or attempts to purchase, or has in his or her possession, any intoxicating liquor, or who is visibly in an intoxicated condition as defined in section 577.001, shall be deemed to have given consent to a chemical test or tests of the person's breath, blood, saliva, or urine for the purpose of determining the alcohol or drug content of the person's blood. The implied consent to submit to the chemical tests listed in this subsection shall be limited to not more than two such tests arising from the same arrest, incident, or charge. Chemical analysis of the person's breath, blood, saliva, or urine shall be performed according to methods approved by the state department of health and senior services by licensed medical personnel or by a person possessing a valid permit issued by the state department of health and senior services for this purpose. The state department of health and senior services shall approve satisfactory techniques, devices, equipment, or methods to be considered valid and shall establish standards to ascertain the qualifications and competence of individuals to conduct analyses and to issue permits which shall be subject to termination or revocation by the state department of health and senior services. The person tested may have a physician, or a qualified technician, chemist, registered nurse, or other qualified person at the choosing and expense of the person to be tested, administer a test in addition to any administered at the direction of a law enforcement officer. The failure or inability to obtain an additional test by a person shall not preclude the admission of evidence relating to the test taken at the direction of a law enforcement officer. Upon the request of the person who is tested, full information concerning the test shall be made available to such person. Full information is limited to the following:
(5) If the test was administered by means of a breath-testing instrument, the date of performance of the most recent required maintenance of such instrument.
Full information does not include manuals, schematics, or software of the instrument used to test the person or any other material that is not in the actual possession of the state. Additionally, full information does not include information in the possession of the manufacturer of the test instrument.
4. The provisions of this section shall not apply to a student who:
(4) Tastes a beverage under subdivision (3) of this subsection only for instructional purposes during classes that are part of the curriculum of the accredited college or university.
The beverage must at all times remain in the possession and control of an authorized instructor of the college or university, who must be twenty-one years of age or older. Nothing in this subsection may be construed to allow a student under the age of twenty-one to receive any beer, ale, porter, wine, or other similar malt or fermented beverage unless the beverage is delivered as part of the student's required curriculum and the beverage is used only for instructional purposes during classes conducted as part of the curriculum.
(L. 1959 H.B. 248 § 1, A.L. 1994 S.B. 693, A.L. 2003 S.B. 298, A.L. 2005 S.B. 402, A.L. 2006 S.B. 725, A.L. 2009 H.B. 62)