Breath tests like this one for drunk driving will be performed all over the country this holiday season.
"Breath alcohol testing is very sensitive."
Attorney Paul Berglin doesn't advocate drinking and driving, but he's seen clients wrongly accused....and in some cases, it's as simple as what is on your breath.
"They may regret that their car was impounded and they were arrested, and they were subjected to the humiliation of being booked in a jail, and forced to take their jewelry and their clothes off."
Kenton Wong is with a company called, forensic analytical services.
"Some of the breath sprays like the Listerine breath sprays, the carrier liquid in those is actually alcohol."
They've seen cases thrown out of court because people accused of drinking and driving had used products containing alcohol, including cough syrup, cold medicine, mouth wash and even lip balm.
"When an individual consumes an alcoholic beverage, some of that alcohol is immediately absorbed into the lining of the mouth."
That also shows up on field breath monitors....commonly called breath-a-lyzers
"It helps the officer to form an opinion on whether someone's impairment."
Police are supposed to watch a suspected drink driver for 15 minutes before giving the test, but in many cases they don't, even a simple belch can throw off test results.
Results higher than the point-oh-eight legal limit, will land a driver in jail, where they would then be required to submit to more elaborate breath or blood tests in custody.
"A breathlyzer test may show that you are under the influence when you're not....it may fail to show that I am under the influence when i am."
Legal analyst Dean Johnson offers this advice to anyone who thinks they may have been wrongly accused.
"Get a good lawyer....one who understands that a dui is a serious matter and that involves serious scientific issues."
Copyright 2009 The E.W. Scripps Co. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.