Thomas Carroll Blauvelt

Breath tests aren’t always reliable

Many people wrongly believe that breath tests are the be-all and end-all when determining whether a person is intoxicated. But, the truth is, breath tests are not always reliable indicators of whether someone is too drunk to drive.

Having a breath test return a false positive – reading you as intoxicated when you were not – is not as uncommon as you might think. There are many factors that can impact the accuracy of a Breathalyzer.


The temperature of your breath can affect your result. While most people have similar breath temperature, some people’s body temperatures are naturally warmer than average. If you are one of these people, your breath temperature may impact a breath test result.

The outside temperature can also affect the test result. The warmer the air temperature, the more likely you are to get a higher blood alcohol content (BAC) reading.

Acid reflex

The chemicals present in individuals with acid reflux are similar to those found in alcohol. If you have acid reflux, the chemicals may result in a higher BAC reading.


What you eat can also affect a breath test. If you have a diet that primarily includes bread or sweets, your result is more likely to be positive for drinking.


If you are a smoker, you are more likely to have high BAC readings during a breath test. Cigarette smoke or any other remaining chemical or substance in your mouth can affect your test results.

In fact, other residue in your mouth can also impact a breath test reading. This includes gum, plaque buildup and even left-over coffee.

Don’t be afraid to question reliability

If breath tests are so easily affected by extraneous factors, it begs the question: are they really that reliable? If you ever find yourself in a situation where you have been given a breath test and are now facing DUI/DWI charges remember, breath tests are not always accurate. You can, and should, challenge the results.

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