When you have been drinking, flashing red lights in the rear-view mirror can induce panic. Many people presume they will be arrested and convicted of DUI because they lack experience dealing with the criminal court system. This inexperience promotes the belief that a DUI arrest along with failed field sobriety and breath tests mean that a conviction is inevitable. This misguided but understandable misconception is promoted by the belief that DUI investigations are based on reliable science. As a practical matter, breath test results frequently are inaccurate for a wide variety of reasons.
There are many factors that might interfere with breath test accuracy, including the inability of the device to distinguish between alcohol and other substances. Some breath testing devices cannot reliably distinguish alcohol from other chemical substances, such as acetone or ketones. A diabetic or someone on a low-carb diet might have elevated levels of these chemical substances in their system, which can result in inaccurate results. It is important to remember that it is not illegal to consume alcohol before driving in the Commonwealth of Pennsylvania. Rather, the criminal offense of DUI involves operating, driving, or being in actual physical control of a vehicle after consuming enough alcohol that the person cannot do so safely, or the driver has a blood alcohol concentration of.08 percent or higher. If you are a diabetic or on a low-carb diet, these factors can trigger a BAC breath test result of .08 percent or above even though your BAC does not exceed the legal limit.
There are other problems that cause unreliable BAC breath test results, including the mathematical formula used to convert alcohol in breath to the volume of alcohol in blood. It is important to know that a breath test machine does not directly measure the alcohol in a motorist’s blood. The breath testing device uses a mathematical ratio called the “partition ratio” to convert the volume of alcohol in the breath of the deep lungs (“alveolar breath”) to the corresponding level of alcohol in a driver’s blood. Generally, this ratio usually is calculated at 2100:1 blood to breath ratio. However, this ratio can be inaccurate for a number of reasons, including a person’s inflated body temperature due to illness.
Another issue that may result in unreliable breath test results is the presence of mouth alcohol. The breath test device is supposed to measure the concentration of alcohol in breath that has been metabolized by the body. Alcohol that remains in a person’s mouth will not have been metabolized, which can cause an abnormally high test result. Breath alcohol might pose a problem if you have very recently consumed an alcoholic beverage or used mouthwash that contains alcohol. This is why officers are supposed to allow for an observation period before administering a breath test. If the officer fails to properly observe this waiting period, the breath test results may be subject to challenge. Even if the officer observes the waiting period, factors such as vomiting, acid reflux, or belching can make mouth alcohol an issue that compromises breath test results. The observation period also will not negate the risk that alcohol might become trapped in dental work, such as feelings or crowns.
These potential flaws in breath testing represent only a few grounds upon which an experienced Pennsylvania DUI defense attorney might challenge the results in your case. Other potential issues include:
- Samples that do not come from the deep lungs (alveolar breath)
- Improper administration of the breath test
- Machine not properly calibrated or maintained.
- Radio frequency interference (FRI)
- Environmental exposure to vapors like paint or varnish
The fundamental point to keep in mind is that there are many ways that an experienced Pennsylvania DUI lawyer might effectively use to challenge breath test results. DUI offenses are treated very seriously and can result in severe penalties. It is important to seek legal advice as soon as possible following a DUI arrest. Call Coover & Scheidemann at (717) 761-1274 to learn how we can help.