What is residual or mouth alcohol?

Residual or mouth alcohol refers to the small amounts of alcohol that may remain in the mouth after consuming alcoholic beverages. This occurs because some alcohol might linger in the oral cavity, around the gums, tongue, or in saliva, even after drinking has stopped. When performing breath tests, such as with the Intoxilyzer 9000, the presence of residual alcohol in the mouth can lead to inaccurate readings, as it may produce higher blood alcohol concentration (BAC) results that do not reflect the true level of alcohol in the bloodstream.

This concept highlights the importance of proper procedures before conducting breath tests, including waiting a certain period after the last drink to ensure that any residual alcohol has dissipated. Understanding residual mouth alcohol is crucial for accurate testing and interpretation of results in the context of DUI enforcement and alcohol monitoring.