What is one of the operator safeguards against residual mouth alcohol?

Ensuring that the mouth is clean is a crucial operator safeguard against residual mouth alcohol when conducting breath tests with the Intoxilyzer 9000. Residual mouth alcohol can lead to inaccurate blood alcohol concentration readings. If a person has alcohol remnants in their mouth from recent consumption or from substances like mouthwash, it can significantly register as a higher reading on the breathalyzer, thus misrepresenting the individual’s true level of intoxication.

By checking that the subject’s mouth is clear of any alcohol before performing the test, the operator minimizes the risk of these misleading results. This is typically verified by asking the subject about their recent alcohol consumption and confirming that they have not consumed anything that could leave traces in their oral cavity. This step is vital to ensure the integrity of the testing process and to produce reliable results that reflect the individual's true blood alcohol concentration.