How Does Mouth Alcohol Affect My Pennsylvania DUI Case?

Most Pennsylvania drivers understand that they may be arrested for driving under the influence (DUI) in Pennsylvania if they have been consuming beer, wine or cocktails prior to driving. Fewer people are aware that they may be arrested based on inaccurate breath test results after consuming other substances, such as:

• Mouthwash
• Tobacco
• Cough syrup

What is mouth alcohol in Pennsylvania DUI cases?

Mouth alcohol can originate from use of these products or consumption of an alcoholic beverage shortly before being pulled over. These substances, as well as residual from the recent consumption of alcohol, or certain medical conditions like acid reflux (and burping), can result in retention of traces of alcohol in one’s mouth that the body has not metabolized.

Breath test devices are designed to analyze the percentage of alcohol in the deep lung, which is referred to as alveolar air. The process of determining the amount of alcohol in one’s blood from a breath test involves use of a formula called the partition ratio to convert the percentage of alcohol in one’s breath to the amount in one’s blood (1:2100). This means the concentration of alcohol in 2,100 milliliters of alveolar breath is presumed to be equal to the concentration in one milliliter of blood. In other words, breath testing devices do not actually measure the amount of alcohol in one’s blood.

The mouth alcohol defense

Alcohol in the mouth that has not been metabolized will contain an extremely high concentration of alcohol, so that the application of this mathematical formula may lead to false high blood alcohol concentration (BAC) results. When mouth alcohol is present from consumption of products like medicines that contain alcohol or because of acid reflux, this may create a basis to challenge your BAC testing results known as the mouth alcohol defense.

The use of this ratio itself is problematic because it is not consistent between different individuals or even within the same individual at different points in time. While prosecutors may argue that mouth alcohol dissipates quickly, this is not necessarily the case when alcohol is consumed shortly before a DUI arrest. Many people have inflated notions regarding the accuracy of BAC breath testing, but there are many ways that the results of breath testing may be challenged.