Why criminal defense attorneys dispute the reliability of the breathalyzer test


Medications can cause false breathalyzer results.


Criminal defense attorneys in Columbus, Ohio understand that while breathalyzer tests are generally reliable, certain factors can cause erroneous readings. So if you think you’ve been wrongfully accused based on a false positive in a breath test, it’s helpful to understand what could have gone wrong, what to do in the future, and how a lawyer criminal defense can help you prove your case. Driving under the influence is a serious charge with serious consequences, so it is crucial that you know your legal rights and what the law can do for you.

What are breathalyzer tests?

Breathalyzers are tools frequently used by police to see if someone has exceeded the legal drinking limit. When a person fails one of these tests, they can face criminal charges related to drunkenness, usually related to driving under the influence. These tests are some of the best evidence a prosecutor can use to show that a person was intoxicated, in order to understand how these tests work. Their limits are crucial for lawyers and clients when building a defense case.

How do breathalyzer tests work?

A breathalyzer requires a person believed to be intoxicated to blow into a tube so that they can determine the amount of alcohol on their breath. The machine then translates the number into your BAC, which is the concentration of alcohol in a person’s blood. This number is then used to determine if someone is over the legal alcohol limit threshold.

How reliable are breathalyzer tests?

Breathalyzers are generally considered reliable, but they may not be as reliable as people think. Studies have shown that these tests have up to a 50% margin of error compared to a person’s actual blood alcohol level. These tests can be particularly inaccurate for some people and in some circumstances. In Ohio, the legal limit is 0.08 for most drivers. Commercial drivers must have a BAC of less than 0.04.

What can cause a breathalyzer to be wrong?

The first thing to note is that breathalyzers are very rarely wrong. They have high accuracy rates; however, there are some scenarios that can cause these tests to give inaccurate results, which you may want to keep in mind.

Medications can cause false breathalyzer results. For example, cough medicine can linger in your mouth and create a higher concentration of alcohol in your breath than in your lungs. It can be the same for mouthwashes. Mouthwashes often contain low amounts of alcohol and you spit out most of the alcohol content. However, the mouthwash can linger on your breath and make you look like you’re intoxicated, even when you’re not.

prescription drugs; image courtesy of TBIT via Pixabay, www.pixabay.com

Certain foods can have a positive effect even if you haven’t consumed alcoholic beverages. For example, sugar-free foods often contain sugar alcohols, and these sugar alcohols can be correlated with positive test results. When you eat overripe fruit, it can add alcohol to your breath. Fermented foods or drinks can have the same impact. So even non-alcoholic beer can make you feel like you’ve had alcohol. Your actual blood alcohol level will not be raised by these foods and drinks, but the breathalyzer will pick up compounds in your breath. You may also have foods prepared with alcohol which can cause false readings. Therefore, many situations can cause false positives because of what you eat.

You may also have a medical condition that causes your breath to confuse breathalyzers. Diabetics, for example, have higher levels of acetone, and since the test cannot tell the difference between ethyl alcohol and acetone, their breathalyzer results may be inaccurate. Extra acid reflux can cause alcohol to back up someone’s digestive system. As a result, someone may have a higher concentration of alcohol on their breath, which does not reflect the actual alcohol in their blood.

Beyond food, drink, and medical factors that can cause your reading to be higher than it should be, there are also technology and maintenance factors that can cause a bad reading. Environmental factors can be another element that leads to a false positive. If certain chemicals are in the air around you, the test may be compromised.

The first problem that can cause an erroneous reading is improper calibration. Police officers should ensure that they maintain breathalyzers and recalibrate them regularly. They have to check that their devices are working as they should and they have to be certified before they can use a breathalyzer. Accuracy tests should have readings below 0.02. If proper calibration is not present, an attorney may suggest that the readings should not qualify.

Some machines may also experience radio frequency interference. The police are often near transmitters and radars and radio. The waves from these devices can cause electromagnetic interference that can affect the accuracy of the breathalyzer. So, seeing if electronic interference is a possibility is one step an attorney can take.

If you are near certain chemicals, your breathalyzer reading may be incorrect. A breathalyzer cannot measure the amount of alcohol in your blood. Instead, they determine your BAC using a formula in addition to an airborne alcohol reading. Unfortunately, tests can’t always tell the difference between alcohol and other compounds. For example, people who work with cleaning fluids, cement, varnish, gasoline, oil-based paint, or other chemicals may experience false positives due to chemical vapors in their breath.

The breathalyzer is not perfectly designed, and while it is often accurate, certain situations can cause a breathalyzer reading to be inaccurate and create false positives. Thus, you should keep these situations in mind if you had a false positive and were unable to figure out why.

Legal experts can help you

A lawyer can help clients build a case and understand how a breathalyzer could have failed. If you think you got a false positive for your breathalyzer test, criminal defense attorneys in Columbus, Ohio can give you additional information and help you understand your options based on the specifics of your case.

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