Skip to Content

Are Breathalyzer Results Always Accurate?


As criminal defense attorneys, we’ve helped many clients who were charged with DWI because of the results of a Breathalyzer test. Often when someone gets pulled over on suspicion of driving under the influence, the first test that the officer administers is a breathalyzer test. But are these tests always accurate?

Breathalyzer tests are used by law enforcement to determine if a driver is under the influence of alcohol. A breathalyzer works by measuring the alcohol concentration in a person's breath. If the concentration is over the legal limit, which is .08 in Texas, then the driver is typically arrested and charged with DWI.

Factors That Can Cause Breathalzer False Positives

While it’s true that breathalyzer tests can be a very useful tool for law enforcement, these devices can generate false positives for a variety of reasons. Let’s examine a few of these reasons below.

Mouth Alcohol

Breathalyzers are designed to measure the alcohol in a person's deep lung air. However, if there is any alcohol left in the mouth, the test will show a higher blood alcohol content than what is actually in the bloodstream. This can happen if someone has recently had a drink or has burped.

Breath Temperature

Breathalyzers are designed to measure the alcohol in a person's deep lung air. However, if the temperature of their breath is above or below the normal range, then the results of the test can be inaccurate. A higher-than-normal breath temperature can lead to a false high reading, while a lower-than-normal temperature can lead to a false low reading.

Medical Conditions

Certain medical conditions can affect the results of a breathalyzer test. For example, if someone has acid reflux or diabetes, then the results of a breathalyzer test may be unreliable.

Calibration & Maintenance

It is important for breathalyzer machines to be regularly calibrated and maintained to ensure that they are giving accurate readings. If a machine is not calibrated correctly, then the results of the test may not be accurate.

Contact a DWI Lawyer for Help!

Breathalyzer tests are not always accurate. There are many factors that can generate a false positive on a breathalyzer test, which can result in a DWI arrest and conviction if not properly challenged.

If you were charged with DWI based on the results of a breathalyzer test, it’s important to consult with a criminal defense attorney who can help you understand your options and potentially challenge the results of the test.

Contact The Alband Law Firm online now for legal assistance.