A Breathalyzer is a device used by police to determine the blood alcohol content of persons—in particular, persons who are driving automobiles—who appear to be drunk. Breathalyzers measure breath alcohol levels, which are considered a reasonable but inconsistent measure of blood alcohol content.Alcohol Problems and Solutions: Breathalyzer Accuracy and DWI/DUI Conviction Rates

On May 11, 2009, a 23 second YouTube video was posted on the gossip web blog TMZ showing a man attempting to drink from a Breathalyzer.TMZ: How to Immediately Fail a Breathalyzer (May 11, 2009)

State laws associated with drunk driving are based on the blood alcohol level—that is to say, the amount of alcohol as a percentage of the total blood in a person's body. That amount may be identified by measuring the amount of alcohol in the breath, and that is what Breathalyzers measure.How Stuff Works: How Breathalyzers Work

Unfortunately, research has shown that the results of breath tests vary considerably from actual blood alcohol content. Further, at least 23% of all individuals tested with a Breathalyzer have a higher BAC reading than their actual BAC.Alcohol Problems and Solutions: Breathalyzer Accuracy and DWI/DUI Conviction Rates

A common myth is that breath testers can be "fooled" (that is, made to generate estimates making one's blood alcohol content appear lower) by using certain substances. An episode of the Discovery Channel's Mythbusters tested substances usually recommended in this practice—including breath mints, mouthwash, and onion—and found them to be ineffective. Adding an odor to mask the smell of alcohol might fool a person, but does not change the actual alcohol concentration in the body or on the breath.

1. TMZ: How to Immediately Fail a Breathalyzer (May 11, 2009)

2. How Stuff Works: How Breathalyzers Work

3. Potsdam University: Breathalyzer / Breath-Tester Accuracy: Facts & Information

4. Potsdam University: Breathalyzer Accuracy and DWI/DUI Conviction Rates

5. BoozinGear.com: Officially Licensed Liquor and Beer Breathalyzers

6. Wikipedia: Breathalyzer

7. YouTube: Breathalyzer Fail (May 11, 2009)