Alcohol test - breath
A breath alcohol test determines how much alcohol is in your blood by measuring the amount of alcohol in the air you breathe out (exhale).
There are various brands of breath alcohol tests. Each one uses a different method to test the level of alcohol in the breath. The machine may be electronic or manual.
One common manual tester requires you to blow up a balloon in one continuous breath until it is full, then release the air into a glass tube. The tube is filled with bands of yellow crystals. The bands in the tube change colors (from yellow to green), depending on the alcohol content. Carefully read the instructions before using the test to make sure you get an accurate result.
If an electronic alcohol meter is used, follow the instructions that come with the meter.
Wait 15 minutes after drinking an alcoholic beverage and 1 minute after smoking before starting the test.
There is no discomfort.
When you drink alcohol, the amount of alcohol in your blood goes up. This is called your blood-alcohol level.
When the amount of alcohol in the blood reaches 0.02 - 0.03%, you may feel a relaxing "high."
When that percentage reaches 0.05 - 0.10%, you have reduced muscular coordination, a longer reaction time, and impaired judgment.
Driving under the influence of alcohol is dangerous. A person with an alcohol level of 0.08% and above is considered legally intoxicated (drunk) in most states. (Some states have lower levels than others.)
The alcohol content of exhaled air accurately reflects the alcohol content of the blood.
Bitterman RA. Medicolegal issues and risk management. In: Marx JA, ed. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, Pa: Mosby Elsevier; 2009:chap 202.
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