5 Major Issues that May Affect a Breath Test Result

One can do a quick search on Google concerning the Intoxilyzer 5000 and discover that there is a great volume of internet literature concerning the many scientific problems with the machine used in Texas to measure a person’s breath/alcohol concentration. As an attorney dedicated to DWI/DUI defense, I have spent numerous hours researching issues concerning the performance or lack thereof, of the Intoxilyzer machine. Below, are the 5 major issues concerning the performance of the Intoxilyzer 5000.

The 5 things that can have a major effect on the performance of the breathalyzer are

  1. Chemical Exposure
  2. Air Bags (aka the Tyndall Effect);
  3. Atkins or low carb diets
  4. Gastro-Esophageal Reflux Disorder (GERD)
  5. Dental Issues.

The first three (chemical exposure, Tyndall Effect, and Atkins or low carb diets) are problems based on interferents that may not be detected by the Intoxilyzer 5000. The last two relate to “mouth alcohol” which is increased alcohol-laden breath results based upon gastro esophagus disorder and dental issues.

Chemical Exposure & Effects on Breathalizers

To explain how chemical exposure might change the results from an Intoxilyzer 5000, one must initial have a basic comprehension of how the Intoxilyzer operates. The fundamental action of the Intox 5000 is infrared spectroscopy coupled with a computer application that transforms a measure in decreased light o units of measurement of alcohol (gm/210 liters). The device does this by mapping infrared light in the sample chamber of the device. When a subject’s breath is added into the specimen chamber, a photodetector measures and reduction in light transmitted from on the side of the chamber to the other side. The value of the decrease in brightness is then inserted into a software application intended to turn the reduced light into grams of alcohol and the turned into an expression of grams per 210 liters of air.

I know that seems like a lot, but it is quite easy. A light bulb on one end of the specimen chamber sends light to the other end. Molecules in the chamber (supposed alcohol from your breath) will stop some of the light from reaching all the way across the chamber. The contrast is then computed by a highly secured computer application to ascertain your breath/alcohol concentration.

It is crucial to note which molecular bonds the Intox 5000 is looking for in its analysis. Particularly, it is looking for the bonds that are connecting the carbon (C) and three hydrogens (H) atoms (CH3). Hence, if a compound contains carbon and hydrogen atoms that merge into a CH3 bonding pattern (like that of alcohol), that compound will possibly be seen as “alcohol” molecules within the specimen chamber. If this is the situation, the breath test will generate a result that is above the real alcohol strength in the person’s blood. Some other composites that have CH3 bonding patterns similar to alcohol are:

  • Acetone
  • Xylenes
  • Isopropyl Alcohol (Isopropanol)
  • Acetaldehyde
  • Toluene
  • Methanol

The substances noted above can be found in daily life in products such as nail polish remover, auto body paint, petrochemical products, floor refinishers and strippers, solvents (home and garage). To influence a breath test, a person must be associated with the chemical source long enough to have had it entered into their bodies. These molecules may be absorbed through the skin and lungs if sufficient exposure occurs. Typically, people with careers such as:

  1. floor refinishers
  2. paint and body technicians
  3. manicurists
  4. computer technicians whose role it is to clean microprocessors with acetone

These jobs and others may have chemical exposure that might influence the result of a breath test.

Airbag Effect on Intox 5000 Breathalizer

The Tyndall Effect is a physics concept used to discuss something known as “colloidal suspensions.” Colloidal suspensions describe a homogenous substance consisting of submicroscopic particles dispersed in another. Unlike solutions, colloidal suspensions exhibit light scattering. A beam of light or laser, invisible in clear air or pure water, will trace a visible path through a genuine colloidal suspension, e.g. a headlight on a car shining through the fog. This is known as the Tyndall effect (after its discoverer, British physicist John Tyndall), and is a special instance of diffraction. Diffraction is a phenomenon that occurs with gases and liquids.

The original airbag design called for the airbag to be packed in a powdery substance to preserve the inflatability of the bag. Over time, the airbag could develop cracks. The powder prevented the cracking and thus made the airbag available for inflation rather than an explosion in the event of a collision. Now airbags are made differently and there is no powder in newer model vehicles.

The Tyndall Effect in breath testing alleges that is a subject is driving in a collision in which the airbag has inflated; the subject would inhale microscopic particles of the powder at impact. All persons who have experienced an airbag will tell you that they get an awful taste in their mouths and sometimes it is difficult to breathe. The effect hypothesizes that these microscopic particles continue to remain airborne for several hours.

If a person has been exposed to an airbag deflation prior to breath testing, some of those microscopic particles of powder will be supplied into the sample chamber at testing. The presence of the powder will “diffract” the light from the infrared source and create a falsely high result in the breath test.

Dental Issues & Effects on Intox 5000

Dental appliances can be a major factor in high breath test results. Like GERD defenses, dental issues concern mouth alcohol. If a person fails a breath test and has had major dental work, this defense should be explored.

Dental appliances include, but are not limited to: braces, retainers, mouth expanders, bridges, and false teeth or dentures. These appliances provide an opportunity for food to become trapped in the mouth after eating. Anyone who has had extensive dental work, such as braces, will tell you that getting food trapped in their teeth is a persistent problem.

When food is trapped within the teeth and alcohol is consumed, portions of the alcohol may become trapped in the teeth or dental appliance. Upon taking a breath test, breath is blown back through the mouth and alcohol molecules can be picked up by the expired breath before introduction into the machine. When this occurs, a false positive test for alcohol may be obtained.

Some studies have demonstrated that some dental adhesives can trap alcohol in one’s mouth for up to one hour. A 15-20 minute waiting period before a breath test can be administered does not eliminate this problem.

There has been insufficient testing on the subject who had both consumed and absorbed alcohol in their system with certain dental appliances to truly know the magnitude of the effect of the dental appliance. Therefore, a dental appliance problem can escape detection by the traditional slope detector on the machine. A “disconnect defense” may be available for a defendant who has dental issues, a high breath test, and a “sober” video.