If you’ve been charged with DWI in Texas, chances are a breath test played a key role in your arrest. But many people don’t realize that breathalyzer results aren’t always as accurate as they seem. From faulty devices to improper administration, there are many reasons why a breath test result can be challenged in court.

Whether you believe the test was wrong or you’re simply looking for help, knowing how breath test results can be challenged could make a big difference in your case.

What can go wrong with a breathalyzer test?

Breath tests are often seen as solid evidence in DWI cases, but they’re not always accurate. According to Texas Penal Code § 49.04, the legal BAC limit for most drivers is 0.08%. Still, several factors can lead to unreliable BAC readings, and understanding these issues could be key to your DWI defense.

Improper calibration

Breathalyzers must be regularly calibrated to ensure accurate readings. If the machine wasn’t properly maintained or tested, the results could be flawed.

Residual mouth alcohol

Mouthwash, certain medications, and even burping can leave traces of alcohol in your mouth, causing falsely high BAC results. Texas law requires officers to observe you for at least 15 minutes before testing to let any residual alcohol clear. If this step wasn’t followed, the results could be challenged.

Medical conditions & breathing patterns

Health issues like acid reflux, diabetes, or asthma can affect breath test results. Even how you breathe—taking a deep breath versus a shallow one—can impact the reading. We work with medical experts to determine whether your health could have influenced the test.

Environmental & external factors

Certain chemicals in the air, like paint fumes or cleaning products, can interfere with breathalyzer sensors.

Even if your BAC was over the legal limit, that doesn’t mean your case is hopeless. An experienced DWI defense attorney can examine the circumstances of your arrest, the reliability of the breath test, and other factors that may help challenge the results.

Defenses that challenge BAC tests

There are several ways to challenge BAC test results in a DWI case, including:

Illegal traffic stop

If the officer did not have probable cause to pull you over or request a BAC test, your Fourth Amendment rights may have been violated. Sometimes, this can lead to the test results being thrown out.

Lack of informed consent

Texas has implied consent laws, meaning drivers agree to BAC testing when arrested for DWI. However, officers must inform you of the consequences of refusing the test. If they fail to do so, the results may be challenged.

Testing errors

BAC tests must follow strict procedures, including proper calibration, storage, and handling. If mistakes were made, we may be able to file a motion to have the test results excluded from evidence.

Don't let a faulty breath test cost you everything - Call Amanda Webb

Breathalyzer results aren’t always as reliable as they seem, and a flawed test could mean the difference between a conviction and a dismissed charge. If you’re facing an arrest or charge for DWI in Texas, it’s crucial to have a knowledgeable attorney review the details of your case.

As an experienced DWI defense lawyer and former prosecutor, Amanda Webb knows how to challenge faulty breath tests and build a strong defense to protect your rights. Don’t face this alone—get the legal help you need. Contact us today for a free case evaluation.

"Amanda Webb and her staff did a fantastic job representing a family member. Her professionalism, attention to detail, and steadfast work for her clients were second to none. I'm grateful to have had her on our team!"
- Craig W. ⭐⭐⭐⭐⭐