Breath Alcohol Test

Alternate Names : Alcohol Test - Breath, Breathalyzer

This test measures the concentration of alcohol in the blood. It does so by analyzing the level of alcohol in exhaled air.

Who is a candidate for the test?

A breath alcohol test may be performed on a person who was involved in a motor vehicle accident to determine if he or she was legally intoxicated at the time of the accident.

How is the test performed?

The test is administered using a kit that includes a balloon and a glass tube filled with yellow crystals. The yellow crystals turn green when exposed to alcohol-containing air.

The person being tested is asked to exhale into the balloon. The person should fill it with one continuous breath. The balloon's mouthpiece is fitted to the end of the glass tube. The air inside the balloon is allowed to flow through the glass tube for one minute. The alcohol content of the exhaled air is measured by counting the number of bands in the tube that have changed from yellow to green. This reflects the alcohol content of the blood.

A calibrated breathalyzer machine is also available to check a person's alcohol level. The person blows into a mouthpiece, and the machine displays the alcohol level. This is more accurate than the balloon type test.