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How accurate are breathalyzer tests?

On Behalf of | Sep 8, 2020 | Drunk driving, DWI

If you are pulled over for suspected drunk driving, more than likely the police will do three things: try to smell alcohol on your breath, have you perform a field sobriety test and have you take a breathalyzer test. U.S. police departments have used breathalyzers, portable machines that measure blood alcohol content, for drunk driving enforcement for decades. But one thing you may not realize is that they are not always accurate.

What’s a breathalyzer’s margin of error?

In fact, according to several studies, breathalyzer tests can have a 50% margin of error. That means if you have a blood alcohol level (BAC) leaving you facing a DWI charge. If your blood alcohol level is .08% but an inaccurate breath tests shows a .16% BAC, you could face additional consequences on top of a DWI charge.

What causes an inaccurate breath test?

Many different factors can cause an inaccurate breath test. Some of these include the following:

  • A breathalyzer machine that isn’t properly calibrated or has been poorly maintained
  • A software error with the breathalyzer machine
  • A police officer who administers the test improperly
  • A driver who recently has used a mouthwash, breath freshener or toothache medicine that causes an inaccurate reading

What can you do to see if your breath test was inaccurate?

If you are facing a DWI charge solely based on a roadside breath test, you want to contact an experienced criminal law attorney. An attorney familiar with defending clients against DWI charges will know how to investigate if your breathalyzer test was accurate or not.

If your breathalyzer test was inaccurate, you could see your charges dismissed, which will be a big relief. A DWI conviction comes with serious consequences, so it’s always valuable to get an attorney’s help to defend against that.