Everything You Should Know About Breathalyzer Tests

woman blowing into breathalyzer and cop watching

Breathalyzer tests are the most common way that police officers evaluate a driver’s sobriety. How much do you really know about how these tests work? What about your rights? And how about what could make these tests inaccurate? Let’s go over everything you should know about breathalyzer tests so you’re prepared for a potential DUI stop.

How Breathalyzers Work

There are a few different types of breathalyzers that vary in how they measure BAC.

Typically, breathalyzers measure the amount of ethanol in one’s breath. The concentration of ethanol then causes a chemical reaction with substances in the breathalyzer. The strength of that reaction will indicate how much ethanol is present in the breath, thus giving a BAC reading depending on that. The stronger the reaction, the higher the BAC.

Police officers are required to go through formal training to use breath test devices to ensure their method of administering the test will yield valid results.

Breath Test Accuracy

Many people believe that because breathalyzers produce a science-based, quantifiable score they are always accurate. This is not the case. There are actually numerous things that can affect one’s BAC score.

Breath tests use one’s breath to measure and estimate their blood alcohol content. Nothing will be as accurate as an actual blood test.

Factors that can skew breath test results include:

  • Medical conditions: if the individual suffers from diabetes, reflux, or a gastrointestinal disorder, this can cause their BAC reading to be higher than what would be reflected from a blood test.
  • Certain diets: even the types of foods you eat could have an influence on BAC scores. High protein diets or fasting can alter your stomach contents and lead to a high BAC reading.
  • Recent burping: burping, vomiting, or any bodily function that brings the stomach contents back up toward the mouth can also push previously consumed alcohol back to the forefront, making it seem like your BAC is higher than it is.
  • Mouthwash: if you’ve recently used mouthwash, breath strips, or another hygenic product that contains ethanol, that ethanol could be misinterpreted by the breathalyzer as drinking alcohol.
  • Calibration: police officers are required to maintain and calibrate their breath test devices. If they don’t, the readings could all be inaccurate and inadmissible.

Many people are unaware that these things can be enough to bring someone over the legal limit. Luckily, an experienced DUI attorney knows and can argue on your behalf if one of these factors influences your case.

Breath Test Refusal in California

All states operate under implied consent laws. This means that if you are asked to take a chemical test, refusing to do so will result in automatic penalties. If you are asked to take a breathalyzer test during a DUI stop and refuse, your license will be suspended for at least one year, and potentially longer if you have a past record of driving under the influence.

However, refusing could be the right thing to do even with the risk of license suspension. It can be easier for your defense attorney to successfully argue for you to keep your driver’s license after breath test refusal than it is to refute BAC scores showing you were over the legal limit. You should take this into consideration when deciding whether or not to take a breath test.

Ignition Interlock Devices

Breathalyzers aren’t only used by police officers. Ignition interlock devices are another type of breath test device that you may be required to use after a DUI conviction. IIDs are breathalyzers that are installed in your vehicle. In order to start your car, you will need to pass a breath test. If you fail, your IID will prevent your engine from starting and you will have to wait a set period of time before you can try again.

The Legal BAC Limit and Breath Tests

If you took a breathalyzer test and it showed you were above the legal limit, you may be wondering if that means you will be automatically convicted of DUI. No, it does not. As you can see from the sections above about breath test inaccuracy, there are still many defense strategies you should use to fight your charges.

If you are facing a misdemeanor DUI charge, you may think it’s no big deal and it’s worth pleading guilty in order to close the book on this chapter of your life. However, you should be aware of the consequences of doing so.

Any time of DUI conviction on your record:

  • Gives you a criminal record
  • Can prevent you from working in some fields
  • Can affect your ability to travel and rent a car
  • Can damage your reputation

Fresno, CA, DUI Defense

If you are facing DUI charges after a failed breathalyzer test, contact Schweitzer & Davidian today. Our Clovis & Visalia DUI lawyers understand that people make mistakes, but so do breathalyzer machines. We will investigate all aspects of your case to craft a creative defense strategy on your behalf; call us at (559) 206-2322 to get started.