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 hand-held 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 quickly.
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.
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 centre or hospital.
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.
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. In Canada, it is an offence to drive when your blood alcohol concentration (BAC) is over 0.08. In most provinces, drivers with BAC levels as low as 0.05 could also get penalties.
To obtain a breath alcohol reading:
If your test has only the glass tube, blow through the tube for the amount of time in the instructions. Use one long breath, not several small breaths. Then look at the coloured crystals to get the reading.
The amount of alcohol in your breath is based on the number of bands that change colour and on the intensity of the colour change.
Follow the specific instructions that come with the device. With most meters, you:
The results appear as a digital readout in a display window. It may show a red or green "traffic light" or an estimated blood alcohol concentration (BAC). After you obtain the first reading, press the reset button and do a second test.
There is no pain from a breath alcohol test.
There is no chance for problems from taking this test. You might feel slightly light-headed after taking the test.
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). Results are ready right away.
To read the glass tube breath alcohol test, count the number of yellow bands of crystals that turn green.
Some electronic devices have a "traffic light" display.
Some devices display the results as an estimated BAC numerical value.
No home test is 100% accurate. The results may not be helpful if you:
A blood alcohol test is more accurate than a breath alcohol test. For more information, see the topic Blood Alcohol.
Driving under the influence of alcohol (DUI) can be deadly. Alcohol is involved in nearly half of all fatal highway accidents. Even mild intoxication can impair your ability to drive safely. At 0.06 BAC, your judgment and physical coordination are impaired. At a BAC of 0.08, your muscle coordination and driving ability are significantly impaired.
How much alcohol it takes to raise your blood alcohol level depends on:
Factors that affect how quickly the blood alcohol level rises in the body include:
Having any amount of alcohol in the blood can cause poor judgment and slowed reflexes. BAC and the effects of drinking alcohol vary from person to person and depend upon body weight, the amount of food eaten while drinking, and each person's ability to tolerate alcohol.
|Estimated blood alcohol concentration (BAC)||Observable effects|
Relaxation, slight body warmth
Sedation, slowed reaction time
Slurred speech, poor coordination, slowed thinking
Difficulty walking, double vision, nausea, vomiting
May pass out, tremors, memory loss, cool body temperature
Difficulty breathing, coma, possible death
0.50 and greater
You can buy breath alcohol tests on the Internet, either directly from the manufacturer or from a company that sells this kind of product. If you have access to the Internet, you can find this information by searching for the type of test or the name of the manufacturer.
Other Works Consulted
- Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
|Primary Medical Reviewer||Kathleen Romito, MD - Family Medicine|
|Primary Medical Reviewer||Brian D. O'Brien, MD - Internal Medicine|
|Specialist Medical Reviewer||R. Steven Tharratt, MD, MPVM, FACP, FCCP - Pulmonology, Critical Care Medicine, Medical Toxicology|
|Last Revised||July 9, 2010|
Last Revised: April 9, 2012
This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.