This Blows

Did you know that handheld breathalyzers are all over market and sold in stores like Brookstone and Sharper Image? They typically cost about $50, operate on AA batteries, and are about the size of a bottle of beer. You blow a steady stream of air into a small tube attached to the device and, voila, a numerical reading appears on the screen.

Breathalyzer machines determine what is known as your Blood Alcohol Content (BAC), which is the amount of alcohol that is in your blood. After alcohol is absorbed into the bloodstream, it leaves the body in two ways—breath and urine. A person's BAC can be measured by taking a sample of their breath, blood or urine. Each test has a specific conversion ratio to determine the exact amount of alcohol in the bloodstream. This ratio is fixed, meaning it does not change based on gender, height or weight.

So, now the million-dollar question: Is this machine accurate? After being a prosecutor for several years and working with these portable breathalyzers on a daily basis, I would say no. First, they are rarely calibrated. Second, portable breathalyzers may misread many other substances in the human breath as alcohol content. For example, diabetics may have acetone in their body, which will result in a positive alcohol sample on this device.

If you find yourself on the side of the road, think twice before blowing into this device. Remember, this test is voluntary, unlike the stationary breathalyzer machines at jails, which can be used against you and can result in a license suspension if you fail to cooperate with authorities. Always consult with a lawyer before giving up your rights!