What occurs when the concentration of alcohol in the mouth exceeds that in the breath?

When the concentration of alcohol in the mouth exceeds that in the breath, it leads to what is known as residual mouth alcohol. This phenomenon occurs because mouth alcohol can mix with saliva and remain in the oral cavity, which can influence breath alcohol readings. The Intoxilyzer 9000 measures the alcohol content in the breath, so if there is a higher concentration present in the mouth compared to what is found in the lungs, it can result in artificially elevated test results.

Understanding that residual mouth alcohol can lead to inaccurate readings is crucial for ensuring the integrity of breath testing. It highlights the importance of proper testing protocols, which may include waiting a specific time after drinking for the alcohol to be absorbed or ensuring that the mouth is clear of any alcohol before administering the breath test. This concept is key in forensic science and law enforcement, as it directly impacts the assessment of an individual's blood alcohol concentration.