Have you ever gargled some mouthwash just before jumping into your car on the way to work in the morning? You might not want to do that. Alcohol-based mouthwash products, like Listerine, can cause you to fail a Breathalyzer test for as long as 10 minutes after use. If you're a driver under the age of 21, the effect could last even longer since the blood alcohol content thresholds are even lower for an underage DWI.
If a Colorado driver fails a Breathalyzer test, police can immediately arrest the driver, book him or her in jail and charge the driver with a DWI offense. It doesn't matter if you're not exhibiting other signs of being drunk. A failed breath alcohol test is enough to bring you into jail.
Of course, you will be permitted to defend yourself against the charge in court, and if you can show that your failed breath test was the result of mouthwash you may be able to get your charges dropped or dismissed. In fact, the defense of having eaten or consumed something (that wasn't an alcoholic beverage), which triggered an inaccurate Breathalyzer reading is a fairly common DWI defense.
However, perhaps it's best to skip the threat of failing a Breathalyzer and switching to non-alcohol based mouthwash products. In fact, many dentists recommend alcohol-free mouthwashes as a healthier alternative to the ones with alcohol.
Breathalyzer test results may be inaccurate for a wide variety of reasons, in addition to mouthwash. If you've been accused of DWI in Colorado, and the only evidence against you is a breath test result, talk to your defense lawyer about different criminal defense strategies that might be able to work for your particular case.
Source: whiteningteethhelp.com, "Can Using Mouthwash Make You Fail A Breathalyzer?," accessed April 28, 2017