In the United States, one of the most common things people do when accused of drinking and driving is completing a Breathalyzer test. This test takes a breath sample to calculate how much alcohol is in the person’s blood.

The problem with this test is that it is not always accurate. It’s more accurate to take blood and test a person’s blood alcohol content, but that isn’t always the method that the authorities use.

Breath tests can be manipulated and incorrect. For instance, if you have just used mouthwash containing alcohol, you will likely blow a positive test result on the Breathalyzer test. The same is true if you have been drinking but burp or have acid reflux. Your reading may be higher than it should be, which could end up causing an arrest.

Another issue is that the test has to be calibrated correctly. Poor calibration can lead to significant issues including false positives and false negatives. Since calibration is so important, officers often give the test two or three times. The results are compared. A good breath test should have results within .02% of each other. More than that in either direction may signify that the test was inaccurate.

What should you do if you’re arrested based on a Breathalyzer test result?

If you’re arrested for an alleged DWI, be prepared to protect yourself. Our website has more information about defending yourself against DWI charges and how to show that a breath test was not accurate, not given correctly or not calibrated accurately for the sample that was taken.

Your attorney can help you look into the case and determine if you have been treated fairly or if the evidence would stand up in court.