If you have a driver's license, you're no doubt aware that you can be subjected to a breathalyzer to check your blood alcohol content if an officer suspects that you've been drinking prior to driving.
However, do you know exactly what a blood alcohol content is and what factors can affect the numbers a breathalyzer returns? Most people don't. While the police would like people to believe that breathalyzers are always accurate, that isn't quite true. Here's what you should know.
What is your "blood alcohol content"?
Your blood alcohol content (BAC) is the measure of ethanol alcohol that's in your bloodstream. A BAC of 0.10% means that there are 0.10 grams of alcohol for every 100 milliliters of blood in your body. In the United States, you're automatically considered too intoxicated to drive if your BAC is 0.8% or higher -- although you can still be charged with a DUI if your BAC is anything higher than a flat 0.0%.
How do breathalyzers determine your BAC?
Unlike blood tests, breathalyzers don't directly measure the amount of alcohol that's in your blood. Instead, they analyze the molecules of ethanol alcohol in your breath and convert that figure to an estimate of your true BAC.
That's one reason that breathalyzers are often controversial and can be effectively challenged in court during drunk driving trials. A mistake in calibration, a faulty machine, an inexperienced officer, and even the technology used in the breathalyzer machine can create problems with accuracy.
What factors affect your BAC as determined by a breathalyzer?
Certain basic factors, like your age, weight, and gender all affect your ability to tolerate alcohol and process it through your body. However, there are many different things that can affect the amount of ethanol alcohol in your breath at any given moment -- and, therefore, affect the reading the breathalyzer gives when you're tested. They include:
- Your rate of consumption -- It's possible for your level of intoxication to continue to rise after you quit drinking. If you drink quickly, your BAC will rise quickly. If you drink slowly, your BAC will rise slowly. That means your BAC could be higher by the time you were tested than it was when you were initially stopped by an officer.
- Your stomach -- If you suffer from indigestion, you may have more ethanol alcohol in your breath than people who don't. When you burp, it forces air up out of your stomach and through your mouth. If you've been drinking, alcohol molecules will tag along -- and increase the number your score on a breathalyzer.
- Your health -- Diabetes can actually cause your body to produce acetone -- which a breathalyzer can't distinguish from the ethanol found in an alcoholic drink. You could be entirely sober and give a high breathalyzer reading!
- Your job -- If you work in an industry that uses acetone, such as painting or some types of manufacturing, you may constantly be exposed to acetone fumes. These fumes can actually gather in your body. That can easily raise the results you get on a breathalyzer.
There are numerous other factors that can create problems with a breathalyzer reading and artificially inflate your BAC. That's why you should consider talking to a DUI attorney if you're charged with drunk driving based on a breathalyzer reading. Never assume that the reading is as accurate as the police like to say.
