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Breath tests: Often used, often wrong

On Behalf of | Apr 10, 2020 | DWI |

Most New York residents know that driving while under the influence of alcohol is an illegal action. Anyone suspected of doing this will be stopped by police and likely asked to participate in sobriety testing. Breath tests are often used by law enforcement officers here. While believed to be highly accurate, the simple truth is the results are often wrong.

Numerous things can contribute to false readings on a breath test. Knowing this, it may be possible to have the results dismissed, which could, in turn, result in the dismissal of DUI charges. How do breath tests work, and what can cause them to provide inaccurate readings?

Breath test basics

Several types of breath tests are on the market. All of them work a little differently, but the purpose of each is to detect alcohol content in a person’s blood. A suspected drunk driver will provide a sample by blowing into the machine, which will then produce a blood-alcohol percentage. For the average adult, anything over .08% will result in an arrest. The BAC needed to arrest underage drinkers or commercial drivers is much lower.

Substances that affect the readout

Several substances that people use every day can mess with breath test results. Some of them are:

  • Mouthwash and other breath fresheners
  • Tobacco products
  • Various medications

If you used any of these products before providing a breath sample, it is something to let your legal team know as soon as possible. This information may help you get your test results removed from evidence.

Human error is a significant problem

Breath test devices are finicky. These devices have to be meticulously maintained; otherwise, their readouts can be far from accurate. For example, an investigation by the New York Times found that machines that have not been appropriately calibrated produce readouts that are roughly 40% higher than they should be. This is undoubtedly an issue that cannot be overlooked. When fighting DUI charges, looking at device maintenance logs can prove helpful in getting breath test results dismissed.

Fight test results

If you are facing DUI charges because you failed a breath test, know that it does not mean a conviction is a sure thing. You have the right to question test accuracy. Doing so could have a positive impact on your case.


Law Offices of Joseph J. Tock