BREATH TESTING PROGRAM IN TEXAS

The breath test machine currently utilized in Texas for DWI investigations is the Intoxilyzer 5000. It works through the process of infrared spectroscopy.

In theory, the machine is supposed to evaluate its accuracy on a continuous basis. Between tests, the machine is programmed to analyze the concentration of alcohol in a known "reference sample" containing distilled water and alcohol. If it predicts this concentration within a certain range, it is assumed to be operating properly. In addition, the machine is programmed to initiate a self-check program designed to identify any outside interference, such as radio waves and unusual chemical substances.

Unfortunately, no independent entity has been able to check the Intoxilyzer's software, since the company that produces the machine has thus far refused to reveal its source code. Questions about accuracy continue to arise as the company now markets a newer version of the Intoxilyzer, touted to be more precise than it's predecessor.

Many problems with the Intoxilyzer have been reported. Mouthwash and tooth implants may unfairly affect the composition of a breath sample. Unlike the "reference sample", upon which the machine determines its accuracy, human breath can contain nearly a thousand different substances. In addition to varying breath composition, people vary in hematocrit level, which can cause breath alcohol concentration to vary wildly. Some people with diabetes, or who are on very low carbohydrate diets or who work around paint fumes may have substances in their breaths that will absorb the same wavelength as alcohol in an infrared spectrometer, skewing the machine's results.

This firm has performed controlled testing on the Intoxilyzer 5000. In one case, a client registered a .18% breath alcohol concentration even though his blood alcohol level was only .05%. This result was achieved after the client had consumed only three 12 oz beers! Naturally, this firm continues to remain skeptical of the Intoxilyzer's specificity and fairness.

For more information visit our DWI web site.