Breathalyzer tests are the foundation of most DUI arrests in Washington, but they’re far from perfect. These devices measure your blood alcohol concentration through your breath, and law enforcement relies on them to determine if you’re over the legal limit. The problem is that breathalyzers can produce inaccurate readings for multiple reasons, and those errors can result in wrongful charges. Understanding how these tests work and where they fail matters if you’re facing DUI charges. The difference between an accurate and inaccurate reading can change the entire outcome of your case.
How Breathalyzer Tests Work
Breathalyzers operate on a simple principle. When you blow into the device, it analyzes the air from deep in your lungs. The device then estimates your blood alcohol content by measuring the alcohol molecules in that breath sample. Most machines used in Washington are infrared spectroscopy devices. They shine infrared light through your breath sample. Alcohol molecules absorb specific wavelengths of that light, and the machine calculates your BAC based on how much light gets absorbed.
The process sounds straightforward, but it requires several assumptions to work correctly. The machine assumes your body temperature is normal, that you haven’t consumed alcohol recently, and that the device itself is properly calibrated. When any of these assumptions is wrong, the reading can be wrong too. A Bellevue high BAC DUI defense lawyer can investigate whether your test was conducted properly. This includes reviewing calibration records, examining the officer’s training and procedures, and looking at your medical history for conditions that might have affected the results.
Common Sources Of Error
Breathalyzer errors happen more often than most people realize. A Bellevue high BAC DUI defense lawyer will look at several potential problems with your test results.
Calibration and Maintenance Issues
Breathalyzers need regular calibration to stay accurate. If a device hasn’t been properly maintained or calibrated according to manufacturer specifications, it can produce readings that are significantly higher or lower than your actual BAC. Washington has specific protocols for how often these machines should be checked, but those protocols aren’t always followed.
Mouth Alcohol Contamination
One of the most common problems is mouth alcohol. If you burp, vomit, or have acid reflux shortly before taking a breath test, alcohol from your stomach can enter your mouth. The breathalyzer can’t tell the difference between alcohol in your mouth and alcohol from your lungs. This can cause falsely elevated readings that don’t reflect your actual blood alcohol level.
Medical Conditions and Diet
Certain medical conditions affect breathalyzer accuracy:
- Diabetes can cause your body to produce acetone, which some devices mistake for alcohol
- GERD and acid reflux bring stomach contents into your mouth
- Low-carb or ketogenic diets produce compounds that can register as alcohol
- Breathing patterns from anxiety or asthma can affect the sample
Environmental and Operator Errors
The testing environment matters too. Radio frequency interference from police equipment can disrupt the device. Temperature variations affect accuracy. And if the officer doesn’t follow proper testing procedures, such as observing you for the required 15 minutes before testing, the results may be unreliable.
What These Errors Mean For Your Case
If you’ve been charged with DUI based on a breathalyzer result, those results aren’t automatically correct. According to the Washington State Patrol, breath test devices must meet specific accuracy standards, but meeting those standards in the lab doesn’t guarantee accuracy in the field. Challenging breathalyzer evidence requires understanding both the science behind these devices and the legal standards they must meet. Many DUI cases have been won by demonstrating that the breath test results were unreliable.
If you’re facing DUI charges in Washington, the breathalyzer reading isn’t the final word. Eastside DUI can review the specific circumstances of your arrest and test to determine if errors may have affected your results. Your case deserves a thorough examination of the evidence, including whether that breathalyzer number actually reflects what happened.
