Self-Test for Breath Alcohol
A breath alcohol test is an estimate of your
blood alcohol concentration (BAC). The test measures the amount of alcohol in
the air that you breathe out (exhale).
You can measure your own
breath alcohol level with a simple handheld device. If the device is calibrated
and used according to the manufacturer's directions, it can provide an accurate
estimate of your blood alcohol level. The home device is similar to, though not
as precise as, the type of test used by police for suspected drunk drivers.
Within minutes of drinking alcohol, your blood alcohol
concentration starts to rise. Unlike food, alcohol is absorbed directly through
the walls of the stomach, goes into the bloodstream, and travels throughout
your body and to your brain. This allows blood alcohol levels to increase
The amount of alcohol in your blood reaches its highest
level about 60 minutes after drinking. But food in your stomach may
increase the amount of time it takes for the blood alcohol to reach its highest
level. Most of the alcohol is broken down in the
liver . The rest of it is passed out of your body in
urine and your exhaled breath.
You can buy breath alcohol devices
to measure your BAC at many pharmacies or through the Internet.
- The manual device is a glass tube (or a balloon
and a glass tube) containing crystals that change color when exposed to alcohol
from your breath. This device is less expensive than electronic
- The electronic meter shows your BAC in a digital
display window after you blow into a glass mouthpiece attached to the meter.
This type of meter is more expensive than the manual type.
Many bars and restaurants provide their customers with free
alcohol breath tests using one of these two methods. The devices are also used
to monitor people in an alcohol rehabilitation center or hospital.
Why It Is Done
The breath alcohol self-test is used to
estimate your blood alcohol concentration (BAC). The results can help you
decide whether it is safe to drive. This estimate of blood alcohol is not
intended to represent your actual driving abilities. Your driving may be
impaired even with a low BAC level, such as below 0.05.
alcohol test offers one piece of information to help you make a safe decision
about drinking and driving. The safest decision is always not to drive if you
have been drinking.
BAC is commonly used by police and other
legal authorities to determine whether a person is legally impaired and should
not drive. A blood alcohol concentration (BAC) 0.08 or greater is
considered legally impaired for adults in the United States. But the legal BAC limit for people under age 18 may be lower, such as 0.02.