In most DUI cases, the breathalyzer data is the prosecution's star witness. Many people think that if the breathalyzer shows an elevated blood alcohol count, there is no way to fight the case. However, breathalyzer evidence is not watertight. There are several factors that can impact accuracy. When breathalyzer data becomes potentially invalid, DUI cases may get thrown out. Even when the machine itself is functioning at peak performance, outside factors can result in a false high reading.
There are several medical conditions that can affect breath tests. Most notable among these is diabetes, which can cause extremely elevated acetone levels. Many types of breathalyzer machines work by zeroing in on ethyl alcohol in a person's breath and are not capable of distinguishing it from high acetone levels. Ketogenic diets may have the same effect, even on people who are not diabetic. Another common condition is gastroesophaeal reflux disease, or GERD, which can cause undigested alcohol in the stomach to back up and infuse alcohol into the breath sample.
In addition to medical conditions, there are environmental factors that can cause a high concentration of acetone in a person's body. If you have been regularly exposed to substances such as paint thinner, you may have enough acetone in your system to cause a false reading.
If you consumed alcohol at some point prior to the DUI stop, it can trigger a high reading even if the amount you drank or the time that passed should have resulted in a BAC below the legal threshold. This can happen for several reasons. If you have gum, dentures or braces, they can retain trace amounts of alcohol that can result in an unreasonably high reading. There are also non-intoxicating substances that contain alcohol, including mouthwash, cough syrup, breath spray and even some asthma inhalers. The use of any of these can cause a false reading.
You should also remember that just because the machine is working fine, it does not mean that the officer operating it is necessarily free of error. People make mistakes; in this case, improper performance of the test can result in inaccurate BAC readings. Failure to operate the machine properly, wipe off the mouthpiece before taking the test, or get information from you about conditions that could affect the test are all fairly common types of user error.
If you failed a breathalyzer test and are now facing a DUI, you might still be able to fight your case. Speak with an experienced lawyer to explore the possibility that the breathalyzer test was not accurate.