Many states require the officer to obtain two tests from the arrested subject, 15 minutes apart, with both tests to be within a range of .002% of each other to ensure scientific accuracy. Missouri, however, is a single test state.

Breath tests are not exempt from the science procedures used in all good analytical testing. Breath tests need to be confirmed, duplicated and controlled.  Quality assurance is a necessity in breath testing.  Scientific safeguards are essential to assure accuracy in breath testing. Although Missouri does not require two tests for confirmation, and duplicity to ensure accuracy, the following essential safeguards are required:

1. A pretest, 15 minute observation period.
2. Blank tests before and after the subject sample and
3. Maintenance and calibration within 35 days of the sample.

1. A lack of 15 minute observation period.
2. Burping/belching during observation period.
3. Residual mouth alcohol by oral intake such as gum.
4. Temperature considerations, variations in subjects body temperature.
5. Contamination of the sample containing volatiles from exposure to paints, solvents, gasoline, diesel fuel, acetone or other exogenous factors.
6. Improper maintenance and calibration of the instrument.

One must spend time with the alcohol influence report, breath test print out and maintenance report. In all cases involving breath and or blood tests a defense expert should be utilized. Do not rely on the state's expert to try and put forward your theory as to the deficiencies of the scientific tests. If you use someone else's mule, you will be kicked.