Don’t drink or gargle before you drive – Alcohol in some mouthwashes can lead to false positives in breath tests!
What is the first thing that you would do if a cop pulls you over and performs a breath test? If you’ve been drinking slightly, the first thought in your head would be to gargle with some mouthwash to mask the alcohol in your breath. Don’t.A common cause of false readings is alcohol-based mouthwash. The Alcohol in mouthwash can actually increase your blood alcohol content (BAC). Listerine mouthwash, for example, is 27% alcohol.
“Incidentally, Listerine mouthwash can cause a false breath-alcohol test result of 0.43% BAC, which is near the level of coma. These effects last as long as 30 minutes to an hour.” (The Prohibition Times, JUNK SCIENCE: GOVERNMENT TESTS FOR DRUNKDRIVING by John Lee)
Research in Wikipedia also confirms this:
“Mouth alcohol can also be created in other ways. Dentures, for example, will trap alcohol. Periodontal disease can also create pockets in the gums which will contain the alcohol for longer periods. And recent use of mouthwash or breath fresheners—possibly to disguise the smell of alcohol when being pulled over by police—contain fairly high levels of alcohol.” (http://en.wikipedia.org/wiki/Breathalyzer)
Of course, the best way to avoid flunking a breath test is to avoid alcohol entirely. But if you decide to drink moderately enough to be able to drive, and anticipate a breath test, it is a good idea to use non-alcoholic mouthwash. So the next time you go out on a date, you’ll be prepared for literally anything – a kiss, a slow dance, or even a breath test.