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How Mouth Alcohol Affects Breath Testing

Posted on in Criminal Defense

Law enforcement commonly uses breath tests (breathalyzers) to determine a suspected drunk driver’s level of intoxication and as evidence in a DWI case. However, these types of tests cannot directly measure BAC since it doesn’t analyze the blood. Instead, they rely on the amount of alcohol particles in a person’s breath when he/she exhales.

Mouth alcohol is a factor that can influence breath tests. It occurs when a small amount of alcohol remains in the mouth or throat, thus contaminating your breath as you blow into the breathalyzer and resulting in a falsely high BAC reading. Although most traces of alcohol are gone within 15 minutes, sometimes alcohol can end up back in the mouth, or something else produces mouth alcohol which throws off the test results.

The following are the most common sources of mouth alcohol:

  • Burping or vomiting – A burp can produce enough alcohol back up into the mouth to influence the test results. Law enforcement is required to conduct a 15-minute observation period before using the breathalyzer. During this time, the officer is supposed to watch that you don’t burp, vomit, or even hiccup whatsoever. Yet, sometimes police ignore this step or fail to pay close attention.
  • GERD or acid reflux – People who suffer from gastrointestinal reflux disease (GERD) experience reflux that forces stomach contents, including any alcohol consumed, into the mouth and windpipe. This mouth alcohol can have an impact on breath test results.
  • Medicines – Medicines, such as nighttime sleeping medication, contain alcohol. Since they often come in the form of thick syrups, the residue from the medication can remain in the mouth much longer. If one of the side effects of a medicine includes drowsiness and wooziness, these symptoms can be mistaken for intoxication.
  • Mouthwash – Listerine and Scope are mouthwashes made with alcohol. Each contains nearly more than 20 percent of alcohol. Additionally, people commonly use mouthwash to cover up the smell of alcohol emanating from their breath.
  • Dental work – Work that was done in the mouth, such as dentures or braces, may trap food, liquid particles, and molecules soaked in alcohol from when the individual consumed an alcoholic beverage.

In order to determine whether or not mouth alcohol is a valid defense in your DWI case, our Plano criminal defense attorney at The Crowder Law Firm, P.C. can thoroughly evaluate your case and determine all of your legal options. Let us help you develop the most effective defense possible on your behalf.

For more information, contact us and discuss your case with our experienced legal team today.

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