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What can affect a breath test’s accuracy?

On Behalf of | Jul 3, 2023 | Criminal Defense

Are breath tests as accurate as they claim to be when it comes to determining a person’s blood alcohol content? This is a question that has sparked much debate and controversy among law enforcement agencies, legal experts and individuals who have found themselves on the wrong side of a DUI charge.

Breath testing hinges on the principle that there is a relationship between the amount of alcohol in a person’s breath and the amount of alcohol in their blood. However, there are several factors that can affect the accuracy of breath tests and lead to potentially misleading results.

Human error

Human error can have a huge impact on a breath test’s results. For one, if someone does not properly calibrate or maintain the device, it may produce inaccurate readings. Additionally, the operator must know how to use the device correctly.

Physiological differences

The physiological differences among individuals can also impact breath test accuracy. Factors such as body temperature, lung capacity and breathing patterns can vary from person to person, which may affect the concentration of alcohol in their breath. This means that different individuals may have different results from the same breath test, even if their actual BAC is the same.

Other substances

Another factor that can affect breath test accuracy is the presence of certain substances in the individual’s mouth or respiratory system. For example, mouthwash, breath fresheners or even certain medical conditions (like acid reflux) may interfere with the accuracy of the breath test results.

While breath tests have a good track record when it comes to accuracy, they provide an indirect measure of blood alcohol content. People must understand these tests’ limitations and challenge their accuracy when necessary.