There are many substances and conditions that can cause a false positive breathalyzer reading. A skilled Orange County DUI attorney can help defend you against false breath test results.
In California, many police officers carry a small machine known as a breathalyzer to take on-the-spot tests of a person’s blood alcohol content (BAC). These tests can be useful in determining if someone is under the influence of alcohol, but they can also be triggered by substances other than alcohol — leading to DUI arrests that simply are not supported.
How a Breathalyzer Works
Contrary to popular belief, breathalyzer tests do not measure alcohol. Instead, they measure any chemical compound that has the methyl group as part of its molecular structure. There are thousands of chemical compounds that contain this group — which can lead to a false positive result if one of these compounds is found on your breath.
When a driver is stopped for a DUI, he is asked to breathe through the tube, where the breathalyzer machine captures a breath sample. Breathalyzer machines typically used infrared spectroscopy to shoot energy through a captured breath sample. Any compounds that contain the methyl group will absorb that energy; the more of that chemical compound is in a breath sample, the more energy is absorbed. The breathalyzer reading is based on how much of that energy reaches the sensor on the other side of the machine. The less light that reaches the sensor, the higher the blood alcohol content (BAC) reading.
However, there is an important flaw in this process: a breathalyzer assumes that if energy is absorbed, the chemical compound present is alcohol. It does not analyze or measure the type of compound absorbing the energy — it merely reports the amount of energy absorbed, which translates into a BAC reading. This can result in a false positive breathalyzer test — and a wrongful DUI conviction — if a person has consumed other substances or has certain conditions.
Breath Fresheners
One of the most common causes of a false positive Breathalyzer test is anything that works to freshen your breath — including mouthwash, gum, mints or cough drops. Mouthwash often contains alcohol, which can translate into a high BAC reading on a breathalyzer test — even if you are completely sober. Gum, mints and cough drops often contain sugar substitutes like sorbitol, which can also trigger a false positive result. If you are pulled over on suspicion of a DUI, resist the urge to freshen your breath — doing so can cause you to be arrested for a DUI!
Medication
Some medications, including over the counter cold and flu remedies, contain alcohol. If you have taken medication, particularly one that contains alcohol or that is applied inside of your mouth (to treat canker sores, for example), you may have a false positive breathalyzer test. If you have recently taken medication, you may be better off refusing to take a breathalyzer test on the side of the road.
Diabetes and Low Carb Diets
Many people with diabetes and some people who are on an extremely low carbohydrate diet have high levels of acetone in their breath due to low blood sugar. While this is a natural occurrence with diabetics and a desired side effect for people trying to lose weight in this way, it may cause a false positive on a breathalyzer test.
When Can You Refuse A Pre-Arrest Breathalyzer
The good news is that most people can refuse to take a pre-arrest alcohol screening. As long as you are over the age of 21 and not on probation for a prior DUI, you are within your rights to refuse to submit to a breathalyzer test before you are arrested. However, if you are arrested, you will be required to submit to a chemical test to determine your BAC; if you refuse, you may face additional consequences.
If you have been arrested for DUI and believe that you may have been falsely accused, contact a trusted Orange County DUI attorney. With an attorney skilled in defending DUI cases, you may be able to challenge the rests of any breath test based on the lawyer’s knowledge of the complex science behind breathalyzers. Contact the Chambers Law Firm today at 714-760-4088 or dchambers@clfca.com to learn more about how we can help you defend against a wrongful DUI charge!
