Test Overview

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. There are different types of devices available. You can get simple devices meant for home use and professional devices like those used by police for suspected drunk drivers.

Within minutes after you drink 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 quickly.

The amount of alcohol in your blood reaches its highest level about 60 minutes after you drink. 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 tube (or a balloon and a tube) containing crystals that change color when exposed to alcohol from your breath. This device is less expensive than electronic meters.
• The electronic meter shows your BAC in a digital display window after you blow into a mouthpiece attached to the meter. This type of meter is more expensive than the manual type.

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). 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.

The breath 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 BAC of 0.08 or greater is considered legally impaired for people 21 and older in most of the United States. But the legal BAC limit for people under age 21 may be lower, such as 0.02.

How It Is Done

Balloon tube test

Wait at least 15 minutes after having an alcoholic drink before testing your blood alcohol concentration (BAC). Trace amounts of alcohol left in your mouth from a recent drink can give false results. So can using mouthwash or mouth spray, such as mouth sprays to relieve a sore throat.

Do not smoke for 1 to 5 minutes before testing your BAC. Do not blow smoke into the device.

Your test kit may have a balloon and a tube or a tube only. The tube contains bands of yellow crystals. The amount of alcohol in your breath is based on the number of bands that change to green and on the intensity of the color change.

1. Check the test expiration date.

   Don't use the test if the expiration date has passed.

2. Follow the instructions exactly.

   Note any special instructions you need to follow before you take the test.

3. Blow into the balloon or the tube.
   • Use one long breath, not several short breaths.
   • With a balloon and tube: Blow until the balloon is full. Then attach the balloon to one end of the tube. Let the air flow slowly out of the balloon and through the tube for exactly 1 minute.
   • With only a tube: Blow through the tube for the amount of time in the instructions.
4. Take the reading.

Take at least two separate readings 15 minutes apart.

Store the testing device correctly. If the device should be stored in the refrigerator or kept in a cool place, make sure you place it in the right kind of storage area.

Electronic meter test

Wait at least 15 minutes after having an alcoholic drink before testing your blood alcohol concentration (BAC). Trace amounts of alcohol left in your mouth from a recent drink can give false results. So can using mouthwash or mouth spray, such as mouth sprays to relieve a sore throat.

Do not smoke for 1 to 5 minutes before testing your BAC. Do not blow smoke into the device.

1. Check the expiration date.

   Don't use the test if the expiration date has passed.

2. Follow the instructions exactly.

   Note any special instructions you need to follow before you take the test.

3. Turn on the meter.

   Let it warm up a few minutes.

4. Take the reading.
   1. Take a deep breath.
   2. Place your lips tightly around the mouthpiece.
   3. Blow steadily and continuously into the machine for the correct amount of time (usually 4 to 6 seconds). Use one long breath, not several small breaths.
   4. See the test instructions for how to read your results and what they mean.

Store the testing device correctly. If the device should be stored in the refrigerator or kept in a cool place, make sure you place it in the right kind of storage area.

How It Feels

You might feel slightly lightheaded after taking the test.

Risks

There are no known risks from having this test.

Results

Results are ready right away.

How much alcohol makes you legally drunk (too drunk to drive) varies among states.

• Most states consider a person 21 or older legally drunk when the blood alcohol concentration (BAC) is 0.08 or greater.
• All states consider people under 21 legally drunk at a lower BAC, such as 0.02 or even lower.

See the test instructions for how to read your results.

Examples of BAC and its effects include:

• 0.05: Slowed reaction time.
• 0.10: Slurred speech.
• 0.20: Hard to walk, nausea, vomiting.
• 0.40: Possible coma and death.

See the test instructions for how to read your results and what they mean.