How Accurate is a Breathalyzer?

By: Staff

When it comes to deciding whether it’s safe to drive after having a few drinks, you need to be very careful. Just because you feel fine doesn’t mean you’re safe to drive. With legal blood alcohol content (BAC) limits in most states at only 0.08, you could feel perfectly fine and still be over the limit. The best way to determine if you’re OK to drive or not is to test your BAC with a breathalyzer. Accuracy is important in these tests as just a small discrepancy could mean the loss of your license.

So, how accurate is a breathalyzer test?

Police officers throughout the country use breathalyzers to determine BAC levels and to make DUI or DWI arrests. The technology that they use needs to be accurate in order to stand up in court.

There are also many different models of breathalyzer-style devices on the market for personal use. These range in price and sophistication from single-use disposable devices right up to professional grade ones. Again, accuracy is of the utmost importance in these devices as well.

In either case, the accuracy of the device depends on the quality and function of the device and the person operating it.

One thing that will affect the accuracy of the reading is waiting the required 20 minutes after eating or drinking before taking the test. If you have just had a sip of alcohol or eaten something that contains chemicals similar to those that make up alcohol, the alcohol will still be in your mouth and you will have a false reading. A test taken right after taking a sip of alcohol or using mouthwash can give a reading higher than fatal levels!

The other most important factor is the function of the breathalyzer device itself. These devices need to be calibrated frequently to ensure their accuracy. If you own an alcohol breathalyzer, be sure to follow the manufacturer’s recommendation on calibration frequency.

All in all, breathalyzer readings are not foolproof, but if used correctly, can be a very close estimate of BAC. The only tests that are more accurate are blood tests and urine tests. The important thing to remember when using a personal testing device is to use it as a guideline only. If you are testing anywhere near the legal limit, play it safe and wait until you get a lower reading.