Breath Tests

Breath Testing For BAC

The breath test is the most often utilized form for testing blood alcohol concentration in Kansas for law enforcement purposes. Currently, Kansas law enforcement agencies are utilizing the Intoxilyzer 8000 as it's breathalyzer. While many states take a minimum of two breath tests to help ensure accuracy, Kansas takes a single breath test. While this leads to unreliable, unsubstantiated tests, they are viewed by the Kansas courts and many jurors as reliable. But the reality is, these tests are often inaccurate. Many things can cause the breath test results to show wrong readings.

Mouth Alcohol Can Effect BAC Results

The Intoxilyzer 8000 does have software intended to detect mouth alcohol and thus abort the test. The Breathalyzer has a "slope detector" which is able to tell when mouth alcohol is present. One would naturally think that mouth alcohol would be just fine as the Breathalyzer is supposed to measure alcohol. But, mouth alcohol actually greatly skews the tests. The Breathalyzer is intended to compute a persons blood alcohol ratio. This is difficult to do as the Breathalyzer doesn't actually ever measure or tests the person's blood. To get an accurate reading, the sample must be free of mouth alcohol and just be a person's deep lung air. To help ensure that no mouth alcohol is present, leading to falsely high BAC results, Kansas requires a 20 minute deprivation period. The person being tested is not to put ANYTHING in their mouth for 20 minutes. This includes alcohol, as well as fingers, water, or otherwise. As a DUI lawyer, this is a big thing I win cases on. Recently, we won a DUI case because the defendant had taken a drink of water 17 minutes prior to taking the Breath Test. If mouth alcohol was present, the machine likely tested that instead of the alveolar air which comes from your deep lungs. A very similar case regarding breath tests was taken to the Court of Appeals, where the driver won his case due to the KDHE not following their own protocol when administering the breath test.

Breathing Patterns Can Effect BAC Results

Inconsistent breathing patterns can effect the results. In fact, hyperventilation and hypoventilation can skew the tests by 15%. If a person takes a big breath and holds it in for just a bit, the breath is heated up and then results in elevated tests results. Officers often instruct DUI suspects to take a big breath of air and demonstrate this very thing which then elevates breath results. On the other hand, if a person was to take very quick and shallow breaths, the results are then lowered. Breathing patterns matter because they effect the temperature of the breath, which in turn effects the breath test results, showing incorrect alcohol concentration levels. In a related note, abnormal lung physiology can obviously effect the BAC results of a Breathakyzer.

Temperature Can Effect BAC Results

Why does breath temperature matter? It's basic scientific principle that when a liquid is hotter, more of it's molecules turn into a gaseous state. Thus, if the breath is hotter, there is more gaseous state than the machine is expecting and results in higher BAC. The breathalyzer assumes the breath is 34 degrees Celsius. Unfortunately, most samples provided are 35 degrees Celsius, resulting in an 8.6% variance. This is a real problem, especially when you tested just over Kansas's legal limit of .08. Even though your BAC was below the legal limit, the results could show you over the legal limit due to you taking a big breath and holding it in preparing to breath into the machine! Imagine if you were sick and your temperature was even higher.

Hematocrit Levels Can Effect BAC Results

Hematocrit varies between individuals and even for a single individual depending on his recent water consumption, sickness, and altitude. Hematocrit is the percentage of red blood cells in a person. Alcohol tends to go to water. Therefore, different Hematorict levels can cause different amounts of the alcohol to go to the breath instead of staying in the blood. A Breath Tests measures breath, and not blood, and therefore gives an estimation of what the persons's Blood Alcohol Level is based on an assumption of Hematocrit levels and making internal computations. However, the Breathalyzer doesn't have any idea what the person's actual Hematocrit levels are. Varying Hematocrit levels can effect the BAC results by 14%.

Radio Frequency Interference (RFI) Can Effect BAC Results

The frequencies caused by police radios are well known factors that cause the Intxoliyzer 8000 to mess up. The Intoxilyzer 8000 does have internal software which is suppossed to be able to detect this and print out an error message.

A Miscalibrated or Poorly Maintained Breathalyzer Can Effect BAC Results

Kansas requires that the Intoxilyzer 8000 be checked every week. Kansas also requires that the machine be certified. Policies and procedures have been installed to supposedly ensure reliability. However, over the years, I have dealt with the people in Topeka, KS in charge of this program and cross examined them in court. The breathalyzers in Kansas and the certifications have come under a lot of scrutiny over the years. Your lawyer can check the Maintenance Logs of the Breathalyzer you were tested on.