Breathalyzer Accuracy? They’ll Drink to That

Filed under: DUI Tags: by Steven F. Fairlie @ February 23, 2012

They’ve been scrutinized and challenged in court, and now Breathalyzer machines are under the legal microscope. Hoping to save the embattled “Intoxilyzer 8000”, officials with the Florida Department of Law Enforcement (FDLE) decided to test the machine’s accuracy. Their plan: Get 15 FDLE employees drunk to prove the skeptics wrong.

Many people assume that if they take the breath test and register a reading over the legal limit of 0.08 that they will not be able to fight their DUI charges. However, just because the driver blew over the legal limit does not mean that a DUI conviction cannot be avoided. In many of these cases, a potential defense strategy is to exclude the fact that a breath test was taken and the results of the breath test, thus leaving the prosecutor without a critical piece of evidence to prove a DUI charge. Such is the case in Florida, where evidence is surfacing that their breathalyzers are the ones that are tipsy.

That’s right, in an ironic fashion it is now the breathalyzers that are being put to the test. Florida DUI attorneys and their experts have been questioning the top officials with FDLE’s alcohol testing program about the problems with the Intoxilyzer 8000, the Breathalyzer used throughout the state after a DUI arrest.

At the top of the growing list of problems with this machine is breath volume. The breath volume in Breathalyzer tests has always been considered important, ensuring that air comes from the deep part of the lungs, where blood and air interact inside the body. The first 1.1 liters of exhaled breath can come from the mouth, throat and esophagus and contain alcohol still in the mouth or other contaminants that can produce artificially high results.

Therefore, when you blow into the machine you must blow 1.1 liters of air in one continuous breath before the machine will determine that a sufficient sample exists and provide an estimate of the subject’s breath alcohol content. You can look at the data and clearly see that the Intoxilyzer 8000 is reporting the individual blew 10, 11, or even 12 liters of air in one continuous breath. Basic science tells us that an individual’s lung capacity maxes out at about 5 liters. Anything with 6 liters or more is completely impossible. So the flow sensor on the Intoxilyzer 8000 instrument that calculates or estimates volume is flawed. The instrument is not calibrated correctly because it is over stating volume. There is also evidence that the Intoxilyzer 8000 is under stating volume as well. In other words, in some instances where the person blew more than the requisite 1.1 liters of air, the Intoxilyzer 8000 reported an insufficient sample.

How can the Intoxilyzer 8000 instrument be trusted at all if the volume of air is incorrect? If the flow is incorrectly calibrated then no reading can be trusted because we will never know whether the instrument really analyzed a sufficient or an insufficient sample. Whether or not FDLE’s scientific party will answer these questions is yet to be determined.

Regardless, the growing concern over the Intoxilyzer 8000’s reliability could potentially affect hundreds of cases where police used the device to obtain a blood alcohol reading. Most likely, it will take a ruling from a higher court, such as the state Supreme Court, to determine whether they will continue to be used in Florida.

This is an example of why it is critical to have an experienced DUI defense attorney on your side when accused of driving under the influence. Breathalyzer machines are not infallible and the rules and regulations regarding their use and maintenance are very specific. Challenging the validity of a Breathalyzer test is one of several defenses considered by the attorneys at Fairlie & Lippy when defending a charge of DUI. For others, please visit our practice page: DUI Defenses.

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