Alcohol Testing Kits: How they Work

alcohol testing kits

Have you ever wondered exactly how alcohol kits measure the amount of alcohol in the blood stream? Here’s a guide on how the kits perform the analysis.

People drink for a number of reasons: to relax, to “let loose,” or to blow off steam. In fact, more than half of Americans have had at least one drink in the last 30 days.

Once it goes down your throat, you probably aren’t thinking of much else except how good that beer tastes. But did you know that, after drinking, alcohol can be detected in blood, breath, perspiration (sweat) and urine?

It’s no surprise that law enforcement and employers have developed tests to determine whether someone’s been drinking, and how much. In fact, alcohol testing kits exist to test alcohol presence in any of these bodily fluids.

And here’s the kicker: there’s another type of test that doesn’t look at your bodily fluids, but at your hair follicles.

Below we discuss the five most popular tests for testing the presence of alcohol.

Breathalyzer Tests

This is probably the test we’re all most familiar with because it’s what cops generally use when they pull someone over on suspicion of drunk driving.

Home breathalyzers can even be fun gifts to give to friends. In recent years, some bars have installed them so that you can compare your Blood Alcohol Content (BAC) to your friends.

But how does it work?

After consuming alcohol, the ethanol is in your blood. When you exhale, small molecules of alcohol exit the little sacs in your lungs and are dispelled into your breath. The breathalyzer analyzes these particles.

The advantages of a breathalyzer are that it’s a minimally-invasive tool, and the result is returned in seconds.

The disadvantage is that surrounding air or recent exposure to, say, mouthwash, may cause a false positive. To prevent this, the user (e.g. police officer) first tests the ambient (surrounding) air.

Often, the person has to blow into the testing device several times. If readings are far apart, the test may be considered invalid.

Blood Alcohol Testing Kits

The most invasive of all alcohol testing kits, this requires an actual blood draw. You read that right: needles.

Because of the invasive nature of this test, it often requires a signature on a consent form. Understandably, this causes issues with people who have had a lot to drink, because this may not be “informed consent.”

Blood tests also require a sterilized area, so they can’t be done roadside. And they should be performed by a trained individual, like a nurse.

For these reasons, it can take awhile to actually run the test and get a result.

The advantage?

It’s hard to dispute a blood reading. Once the blood is drawn, results are considered highly accurate.

Saliva (aka Spit) Tests

Just like blood, another bodily fluid – saliva – contains ethanol after you’ve been drinking. And this isn’t alcohol that’s still in your mouth from your last time consuming alcohol; instead, it’s the alcohol that’s gone through your bloodstream and is now excreted in saliva.

Quick and portable, saliva tests are popular at employment sites or doctor’s offices. This alcohol test is painless and non-invasive, requiring only a cotton swab like most of us have in our home bathrooms.

The wait time is only a couple of minutes, and the test is up to 98% accurate. Of course, this test can be complicated by certain food intake or mouth infections.

Urine Tests

This test is probably the least accurate of the four alcohol test options because it can take awhile for alcohol to show up in urine, and once it doesn’t appear, it doesn’t stick around for long.

There are two types of urine tests. One of them answers a simple question: is alcohol present in the urine? It’s a simple yes or no.

But there’s an issue with this. Certain yeasts (bacteria) in the body may produce their own sort of alcohol, which can show up as a positive on urine alcohol testing kits. This is a particular challenge for people with certain health issues, like diabetes.

The second, more popular urine test, looks for a by-product of alcohol, known by the fancy name of Ethyl Glucuronide (EtG.) In the case of a yeast infection, this test won’t register as a false positive.

Another advantage to this test is that it can identify alcohol in the system for up to 3 days.

Either way, urine tests are considered moderately invasive (after all, you have to pee in a cup). But results are quick, coming back in only several minutes.

Hair Follicle Tests

The length of time that alcohol stays in your system depends not only on how many drinks you have, but your size (height and weight,) your gender, what you’ve eaten that day, and your overall metabolism.

Your hair holds the secret longest, folks. That’s right: alcohol consumption can be detected in your hair follicles for up to 90 days.

This test also measures EtG instead of actual ethanol, to help with false positives. It also takes about 5 days for the EtG to show up in hair follicles, so a test taken right after leaving the bar won’t show much (the breathalyzer is a different story!).

Because of the long timeframe to detect alcohol consumption with this test, it’s becoming more popular with employers and court systems.

Unfortunately, this test can be somewhat invasive. Typically, 40-70 strands of hair are needed for this test, and they are taken from different parts of the scalp.


Results aren’t always quick, either. Because the hair needs to go off to the lab, results may take a few days.

Check Out Our Products Today

As we move into the holiday season, many of us are thinking wisely about our own intake and the various products on the market that can help monitor it.

Just remember: your safety is number one! Never drink and drive.

We offer alcohol testing kits and other products related to drug and alcohol testing. Check out our products today!

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