What Is a Breath Alcohol Test?

Alcohol enters your stomach and small intestine when you consume it. It is absorbed into your bloodstream, which then transports it throughout your body, including to your brain and lungs. When you breathe, you exhale it. A breath alcohol test determines the amount of alcohol in the air you exhale. This measurement is used by the device to estimate the amount of alcohol in your blood. That number is known as your BAC, or blood alcohol content. It may go up as soon as 15 minutes after drinking. BAC is usually highest about an hour after you drink.

Why Is It Used?

As your BAC rises, you can get clumsy and take longer to react. You may not make good choices, either. These things make driving dangerous. In every state but one, it’s illegal for a driver over the age of 21 to have a BAC above 0.08%. As of December 2018, Utah’s BAC level will be 0.05%. All states have zero tolerance laws for drivers under 21. If you’re speeding, in an accident, or weaving on the road, local police may suspect you of driving under the influence, or DUI. They can use a device known as a Breathalyzer to test your BAC right at the scene of an accident or on the side of the road if they pull you over.

Are There Different Kinds of Tests?

Manual or electronic tests are both possible. The majority of cops utilize an electronic gadget similar to a walkie-talkie. When you blow into a mouthpiece, it provides you an instant readout. It's possible that you'll be asked to repeat this a few times so the officer can acquire an average reading. It only takes a minute and is completely painless.

A balloon and a glass tube filled with yellow crystals are used in the most popular manual test. You inflate the balloon and let the air out via the tube. Depending on how much alcohol is in your system, the crystal bands in the tube change color from yellow to green.

Check the instructions included with the device to read results. Generally, one green band means your BAC is under 0.05%, which is within the legal limit to drive. Two green bands indicate that your BAC is between 0.05% and 0.10%, and three bands means it’s over 0.10%.

You can buy either type of test for yourself if you want to make sure you’re safe before you get behind the wheel. The manual ones are less expensive.

Is It Accurate?

Not always. There are a few things that could cause an error in the reading.

Trace levels of alcohol in your mouth could cause an inaccurate result if you have a drink 15 minutes before the test. Smoking can also have an impact on the outcome. Mouthwash and breath fresheners, for example, can include alcohol.

Sometimes the machines need to be recalibrated or have batteries replaced. These possibly could affect the reading.

Some tests have software that needs to be updated occasionally and can cause glitches.

Fuel cell technology is used in professional breath alcohol tests, such as those carried by police officers. They're the most precise. A blood or urine test, on the other hand, is more accurate than a breath test.

Things That Affect BAC

How fast your BAC rises and how long it says that way depend on several things:

Your weight. The heavier you are, the more water is in your body. The more water, the more the alcohol gets diluted.

Your gender. Alcohol doesn’t affect men and women the same. Men have higher levels of a stomach enzyme that helps break down alcohol, so they process it faster. Women typically have less water and more fat. Hormonal changes in women also can affect the BAC.

How many drinks you had, how strong they were, and how fast you drank them. The more you drink each hour, the faster your BAC rises.

How much you ate. A full belly, especially high-protein foods, will slow the processing of alcohol.

What Do the Results Mean?

If a police officer gives you a breath alcohol test and your BAC is over the legal limit of 0.08%, you may be arrested and charged with driving under the influence.

You also may be asked to provide a blood or urine sample for further testing to determine a more accurate BAC.