Along with the three field sobriety tests, the breathalyzer test is a common method law enforcement agencies across the US use to assess whether a driver has been drinking alcohol excessively. When you exhale into a breathalyzer, it can estimate the amount of alcohol in your bloodstream by measuring how much of it is on your breath.
However, this is an imperfect system. Alcohol can end up on your breath without making its way to your bloodstream, such as when you use mouthwash. In such a situation, you could fail a breathalyzer test while perfectly sober.
If that does come to pass, there are steps you can take to ensure you don’t end up with a DWI conviction.
How Can Mouthwash Cause a Positive Breathalyzer Result?
Many mouthwashes contain alcohol, as it works to kill bacteria in the mouth. Certain brands are over 25% alcohol by volume; that’s as much as some weaker liquors. When you use mouthwash, trace amounts of it can remain in places like your teeth and under your tongue after you spit it out.
Breathalyzers are designed to detect alcohol in alveolar air, which comes from the part of your lungs in which the gases you breathe enter and exit the bloodstream. Alcohol is only present in this air in small quantities, so breathalyzers must be sensitive in order to detect it. This means mouth alcohol is often sufficient to produce a positive result.
Using mouthwash is not the only activity that can cause you to fail a breathalyzer without consuming alcohol. Some inhalers, breath sprays, and even certain chocolates contain alcohol.
What Happens if I Fail a Police Breathalyzer Because of Mouthwash?
You have the right to ask the police officer administering your breath test to carry out another after a short period has elapsed. If you can pass a second test within 30 minutes of failing the first, this makes it more likely that mouth alcohol was the cause of your initial failure. The trace of alcohol that mouthwash leaves on your breath tends to dissipate within 10-15 minutes. In Minnesota, as in other states, DWI offenses occur when a driver’s blood alcohol concentration (BAC) is over 0.08%.
Even if you cannot pass a test, the breathalyzer is just one piece of evidence against you. You may be able to work with your lawyer to build a case that proves you were not, in fact, driving drunk.
Does Mouthwash Affect Ignition Interlock Devices (IIDs)?
Ignition interlock devices (IIDs) work by disabling your vehicle for a period if you cannot produce a breath sample that’s clear, or almost clear, of alcohol. The blood alcohol concentration (BAC) limit on Minnesota IIDs is 0.08%, the same number that applies to initial DWI offenses. While there are different mechanisms in different IIDs, many use the same kind of technology as police breathalyzers.
If you have an IID installed in your vehicle, it might be a good idea to use non-alcoholic mouthwash, or to wait 15 minutes between using an alcoholic brand and getting into your car. It could also help to wash out your mouth with water before blowing into the device.
If you fail an IID test after using mouthwash, you should contact your program provider as quickly as possible to explain what happened. Some IIDs will perform a retest five minutes after a failed reading, so if you rinse your mouth out between tests you may stand a better chance of passing the second.
Responding the Right Way to an Unfair Breathalyzer Result
If you fail a breathalyzer test during a police stop or on your car’s ignition interlock device despite not having consumed alcohol, your first instinct may be to panic. However, you should remember that you’re entitled to plead your case and expect fair treatment before the law. Hiring an experienced Minnesota DWI attorney is the best way to ensure a simple mistake doesn’t leave you with a costly DWI or IID violation.
To find out more, contact us today. We’ll carry out a free initial review of your case.