Tuesday, 06 April 2010 06:19

False Breath Test Results in DUI Cases

Written by
Rate this item
(0 votes)
One of the big problems with breath testing in DUI cases is the issue of mouth alcohol contamination of the sample. When I use the word breath testing I refer to both the use of the preliminary alcohol screening device and the evidential or tabletop test. "Mouth alcohol" refers to the presence of any alcohol in the mouth or airway during breath testing after having been arrested for DUI. If even small amounts of raw alcohol exist during a breath test, then the results will show a false high reading by the internal workings of the device. This is because the breath testing device assumes that the alcohol is from the deep part of the lungs (the alveolar air sacs), Indeed, in California, Title 17 of the Code of regulations requires that the sample be "essentially alveolar in nature". The breath sampling machine multiplies the amount of alcohol that is blown into it 2100 times to extrapolate what a "normal" person's blood alcohol would be. Therefore, even a microscopic amount of alcohol breathed directly into the machine from the mouth or throat instead of from the lungs can have a huge impact on the test result, producing an erroneously high result.

Mouth alcohol occurs most commonly by belching, burping, hiccupping or vomiting within 20 minutes before taking the test which can bring vapor from alcoholic beverages still in the stomach up into the mouth and throat. Some breath freshener products such as Binaca and Listerine have alcohol in them and their use can also cause similar problems; cough syrups and other cold products also
contain alcohol. Dental bridges and dental caps can trap alcohol as well. Blood in the mouth from
an injury is yet another source of inaccurate breath test results: breathed into the mouthpiece, any
alcohol in the blood will be multiplied 2100 times. Some people with health problems can also be
adversely affected. For example people with GERD or chronic "acid reflux" can create falsely
elevated blood alcohol reading due to their condition and not even know it.

This problem is one that has plagued the area of breath testing in drunk driving cases for many years. Despite efforts by the breath test machine manufacturers to detect this problem, it continues to result in many convictions for DUI even though the individual may in fact be innocent.


Due to the complexity of this defense it is advisable to be represented by an attorney who is familiar with this area. When handled correctly, this defense can prevent an innocent person from being convicted of a DUI or Drunk Driving. If you have questions regarding your particular case you should speak to an experienced DUI Lawyer.


Read 508 times
Login to post comments