Quick Look at Continuing Breath Alcohol Test Problems

April 10th, 2014 Allen Trapp Posted in Breath Tests, Intox 5000, Chemical Test No Comments »

It is now well established that a subject’s manner and mode of breathing just prior to providing breath for analysis can significantly alter the concentration of alcohol in the breath sample.  Hyperventilation has been shown to lower the breath alcohol concentration by as much as 20%.  Holding your breath for a short time (20 seconds) before exhalation increases the alcohol concentration in exhaled air by as much as 15%. Be on the lookout for forced agreement between the two breath samples. An officer can watch the BrAC rise on the second sample. When it gets close to the reading of the first sample, he can tell the subject to stop blowing, to ensure that the two samples are not more than .02 apart.

Since at least 1950 34°C has been the accepted breath temperature used for breath testing purposes. Professor Harger made this decision in 1950 after examining six subjects whose recorded range was between 31°C and 35°C. However in 1996, a much larger study of 700 subjects concluded that the average was 35°C-a full degree higher than Harger’s adopted temperature. Fox & Hayward compared the effects of hyperthermia and hypothermia on breath alcohol results. They found that average increase in Breath Alcohol Concentration over Blood Alcohol Concentration was 8.6°C for each degree Celsius increase in deep-core body temperature.

These are just two of the more basic issues we encounter in DUI defense. Although some lawyers think “anyone can do DUI,” the odds are that those lawyers are not familiar with these issues and will not invest the work required to gain the knowledge. No matter where you are, if you interview a lawyer and he or she cannot discuss these matters, keep looking.

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More on Breath Temperature

July 24th, 2009 Allen Trapp Posted in Breath Tests, Intox 5000 No Comments »

     As far back as the 1930’s it was recognized that re-eqilibration of the alcohol and breath occurs at the lower temperature (as opposed to core body temperature) of the upper respiratory tract during expiration in such a manner that temperature controls the alcohol content of the expired alveolar air.  In the earliest “drunk-o-meter” invented by Professor Rolla Harger of Indiana University it was assumed that 61.5% of the collected breath sample was alveolar air and that 2100:1 was the appropriate partition ratio.  Partition ratio in this instance refers to the amount of alcohol in the blood compared to the amount in the breath.

     During a twenty-year period he and his colleagues conducted numerous experiments, which confirmed that the partition ratio varies at different temperatures.  In other words, breath alcohol test results will be different at different temperatures.  During all of this testing it was assumed that the average expired breath temperature was 34 degrees centigrade (Celsius), which in turn led to the conclusion that the average blood:breath partition ratio for breath alcohol testing is 2100:1.  The National Safety Council adopted this number in 1952, and so it has become engraved in the statutes of the several states over the last half century. 

     Researchers have questioned the use of a constant breath temperature and partition ratio since at least 1975.  Beginning in that year leader experts in the field began to question whether airway alcohol exchange played a bigger role in breath alcohol testing than was previously recognized.  More and more research has proven that the average expired breath temperature is closer to 35 degrees Celsius, including the German study of 1995 and a similar study sponsored by the Alabama Department of Public Safety three years later.

     As a result of the Alabama study that state adopted the Draeger 7110, which makes an adjustment for an elevated breath temperature.  In fact, the Alabama testing sequence includes two breath samples (like Georgia), two methods of analysis for every breath test, specifically infrared and fuel cell (unlike Georgia), breath temperature monitoring and correction for each breath test (unlike Georgia), and two calibration checks at .02 and .08 at the time of each breath test (unlike Georgia).  In addition, a comprehensive data collection package including breath exhalation profiles was included in the software designed for Alabama DPS (unlike Georgia).  The downloaded data includes a total review of all breath tests in the State (unlike Georgia).   This enables the state to identify and address both instrumental and operational problems.  In Georgia there is a handwritten log on which officers may make entries, but nobody knows how often it is used or how often it is ignored. 

     The Alabama program is truly a model program other states should emulate.  Before switching to the Draeger, Alabama (like Georgia) used the Inoxilyzer 5000.  That makes me wonder: If it’s not good enough for Alabama, why are we still using it?

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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Does the Breath Test Really Measure Deep Lung Air?

March 11th, 2009 Allen Trapp Posted in Breath Tests, Intox 5000, Chemical Test No Comments »

     One of the assumptions upon which breath alcohol testing has rested since the 1950’s is the belief that the instruments measure “deep lung” or alveolar air.  This outdated assumption has been eroded as research over the past two decades has yielded a greater understanding of the exchange of highly soluble gases by the lungs.  No longer can it be assumed that alveolar air is in equilibrium with blood alcohol simply because the breath test reading reaches a plateau. 

     The findings of Dr. Michael Hlastala of the University of Washington confirm that during inspiration the relatively cool and dry air being inhaled becomes warmer and absorbs liquid in the airways.  This air also absorbs soluble gas dissolved in the airway tissue.  During exhalation the air is cooled and dehumified.   The alcohol present in a breath sample comes entirely from the lining of the airways.  This mucus and tissue, not the blood in the lower part of the lungs, is the source of “breath alcohol concentrations.”

     Further research has shown that breath alcohol concentration continues to rise as a person exhales until he or she cannot exhale any longer, which causes the flattening or plateau of the breath alcohol concentration.   It has also been confirmed that the average directly measured partition coefficient for alcohol in blood at 98.6 degrees Fahrenheit is 1756:1, not  2100:1 as asssumed by the Intoxilyzer 5000.   Also of significance is the discovery that an increase in exhaled volume beyond the minimum required by a breath testing instrument results in an increased breath alcohol reading and a decreased blood to breath partition ratio.  For those with smaller lung capacity, these findings also have negative consequences because a greater portion of their vital capacity (maximum volume of air that can be inhaled and exhaled) is necessary in order to generate a printed result.  On the other hand, those with larger lungs will benefit from an unfair advantage. 

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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Alcohol is not Always Ethanol

March 11th, 2009 Allen Trapp Posted in Breath Tests, Intox 5000, Chemical Test 1 Comment »

     Ethanol or ethyl alcohol contains two carbon atoms linked to hydrogen atoms (methyl groups) and one oxygen atom linked to a hydrogen atom (hydroxyl group).  Most infrared breath testing devices rely upon the absorption of light at the 3.39 and 3.48 micron wavelengths, which are characteristic of the carbon-hydrogen bond,  for the determination of breath alcohol concentration.   However, at these wavelengths the infrared energy will be absorbed by many organic molecules containing carbon atoms bonded to hydrogen atoms, including hexane, toluene, and methyl ethyl ketone. 

     Experiments have shown that the Intoxilyzer 5000 will report these substances as ethyl alcohol and will print what purports to be a breath alcohol concentration.  In other words, the results for substances other than ethyl alcohol are reported as alcohol.  The research leaves little doubt that the instrument simply cannot distinguish the different alcohols from each other.   The numerical results are always reported as grams of alcohol per 210 liters of breath even when there is no ethanol in the breath sample.  

     The results for these interfering substances once again demonstrate the non-specificity of the Intoxilyzer 5000 and any other breath analyzer that relies on the the absorption of energy by the carbon-hydrogen bond in the 3.39 and 3.48 micron range.   

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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Infrared Breath Testing Devices: Common Problems

October 21st, 2008 Allen Trapp Posted in Breath Tests, Intox 5000, Chemical Test No Comments »

     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
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