Infrared Breath Testing Devices: Common Problems

     A major issue with infrared breath testing devices is that they not only detect the ethyl alcohol found in alcoholic beverages but also in other substances that have a similar molecular structure. Stated differently, these devices identify any compound containing the methyl group molecular structure. And the issue with this is that more than one hundred compounds can be found in a human’s breath at any one time and 70% to 80% of these compounds contain the methyl group molecular structure. The consequence of this is that these methyl group molecular structures will be incorrectly identified and labeled as ethyl alcohol. Interestingly, the more ethyl group substances the breathalyzer detects, the higher the false blood alcohol content estimate will be.

     The National Highway Traffic Safety Administration (NHTSA) has found that people who are diabetics or dieters can have acetone levels that are hundreds, if not a thousand of times higher than people who are not diabetics or dieters. The key issue here is that acetone is one of the many substances that can be falsely detected as ethyl alcohol by some breathalyzers.

     There’s also a variety of products found in the environment that can lead to erroneous BAC results with these machines. Some of these products include substances or compounds found in cleaning fluids, celluloid, gasoline, paint removers, and in lacquers. Other common substances that can result in false BAC levels are alcohol, vomit, or blood in the person’s mouth. False BAC readings can also be caused from electrical interference, dirt, smoke, cell phones, police radios, moisture, and tobacco smoke.

     Infrared breath testing devices can be very sensitive to temperature and will result in false readings if they are not adjusted or recalibrated to compensate for ambient or surrounding air temperatures. Moreover, the temperature of the person being tested is also significant. More specifically, each degree (in Centigrade) in the subject’s body temperature above 34 C (98.6 Fahrenheit)  can result in a relatively large elevation (about 8.6%) in apparent BAC.

Written by Allen Trapp who is board certified by the National College for DUI Defense and the author of Georgia DUI Survival Guide Visit Website Written by Allen Trapp who is board certified by the National College for DUI Defense and the author of Georgia DUI Survival Guide Visit Website

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