4 ways a breath alcohol test can be inaccurate

Breath alcohol tests in Wisconsin are not always an accurate depiction of someone’s blood alcohol concentration.

The amount of alcohol in someone's blood is an important factor when he or she is suspected of operating while intoxicated in Wisconsin. According to state law, someone who is younger than 21 is not permitted to have any detectable amount of alcohol in his or her system. People of legal drinking age could be charged with a crime if there is 0.08 percent or higher found.

One of the issues with testing for someone's alcohol concentration is that a breath alcohol test is not always accurate. The following illustrate the ways in which these tests may fail:

1. A high margin of error

According to the National Motorists Association, breath tests are often used to symbolize how much alcohol someone has in his or her bloodstream. However, a breath test does not measure blood; it measures the amount of alcohol in the air. The NMA points out that according to research, a breath test's margin of error can be as high as 50 percent when comparing the test results with actual blood alcohol concentration. Therefore, someone could register a 0.08 on a breath test when in actually, he or she has a legal limit of 0.04 percent.

2. Poor administration

There are rules in place that dictate how law enforcement officers in Wisconsin may administer a breath alcohol test. The machine must be calibrated before every use, resetting the device to get an accurate reading. Further, if there is vomit or blood in the person's mouth or the person belches during the test, the results may not be accurate.

If any of these takes place, the officer is supposed to wait for 15 minutes before running the test again. Failing to do so could garner charges. In the event of a conviction, the defendant could file an appeal based on these grounds.

3. Misinterpreting substances

A breath alcohol test picks up on any traces of alcohol in the mouth. However, mouthwash and even certain foods, such as bread, can be mistaken for alcohol. Having any residual alcohol or substances that could be read as alcohol could result in a higher BAC and a drunk driving charge.

4. Medical conditions

People with certain medical conditions may be more likely to register as having an illegal blood alcohol concentration. For example, diabetics tend to have a naturally higher level of acetone in their systems. Breath alcohol tests can misread acetone as alcohol.

There are a number of other ways that a breath alcohol test can paint an inaccurate picture of a driver's sobriety. Environmental factors, such as paint fumes, can trigger a positive reading.

The consequences of drunk driving in Wisconsin are stiff and can have lasting effects. Anyone who is facing such a charge should contact a criminal defense attorney as soon as possible.