Let’s say you’re on a date. You and your date decided to go our to an Italian restaurant, where you order a pizza and a glass of wine. After dinner—concerned about the effect that the anchovies and garlic had on your breath—you take out one of those breath-freshener sprays that you bought for moments such as this one. You and your date then get in your car and drive off.
You would probably never guess that—if you were unfortunate enough to be pulled over and asked to take a breathalyzer—the result would probably be well over the legal limit. The most surprising part is that the glass of wine that you had at dinner had nothing to do with it. More surprising still, the breath-freshener wasn’t the only culprit: it was also the pizza!
Let’s start with the breath-freshener. One of the biggest problems with breathalyzers is they cannot tell the difference between alcohol that comes from the mouth (which does not detect impairment) and alcohol from the lungs (which does). Mouthwash and many breath-fresheners contain a high percentage of alcohol, which can stay in your mouth for a while. Numerous studies have shown that using either mouthwash or breath-fresheners can result in blood alcohol readings that were not only significantly above the legal limit but would have killed the person if the results were accurate.
One study was done with Listerine mouthwash, where seven subjects were made to rinse their mouths with Listerine for 30 seconds. Each subject then took a breathalyzer test one minute, three minutes, five minutes and ten minutes after they used the mouthwash. After five minutes, the average test result was still well above the legal limit. (“Field Sobriety Testing: Intoxilyzers and Listerine Antiseptic,” The Police Chief July 1985 page 70) In another study, the pocket breath-freshener spray Binaca was used instead, but the results were basically the same.
It might not strike you as all that surprising that putting alcohol in your mouth in the form of mouthwash and breath-fresheners would create a false breathalyzer reading. What about bread? Phil Price, an Alabama DUI attorney, did some tests of his own where he consumed several types of bread products and took a breathalyzer with one of the most commonly used devices on the market, the Intoxilyzer 5000. Unbelievably, he obtained results as high as 0.05%. (“Intoxilyzer: A Bread Testing Device?” 15(4) Drinking/Driving Law Letter 52, 1996). The Washington State Toxicology Laboratory did its own studies and wound up confirming Price’s experiments. (“Ethanol Content of Various Foods and Soft Drinks and their Potential for Interference with a Breath-Alcohol Test”, 22 Journal of Analytical Toxicology 18, 1998.)
You might be wondering why bread products would have this effect. The theory of the Washington State scientists was that, while most of the alcohol created by the yeast goes away in the baking process, there is often residual alcohol that isn’t baked off.
The moral of the story—besides the fact that you should cut down on carbs and resist the pungent foods—is that the breathalyzer tests do not provide the hard proof that so many people assume they do.