Presence of "Mouth Alcohol" can lead to an Inaccurate Breathalyzer Result

Breath testing is commonly used to check blood alcohol levels in DUI cases. People also confuse breathalyzer test results with blood alcohol levels (BAC) without realizing the fact that these two terms are significantly different from each other. Breath tests are not as accurate or reliable as blood tests when it comes to checking a DUI suspect for BAC levels. This is because breathalyzers do not read your BAC but use a complex formula that takes the amount of alcohol and multiples it by 2100 to get the results.

All breath testing machines assume that the breath comes from the lungs, without taking any external factors into consideration. This is where the problem arises. In most cases, the breath sample is not the air which comes directly from the alveoli. It can get affected by the presence of “mouth alcohol”, which can give a much higher reading that it should be. Studies show that 23 percent of blood alcohol readings taken with a breathalyzer are higher than the actual readings. Breath tests can vary as much as 15 percent from actual alcohol concentration in the blood.

How do Breathalyzers calculate BAC?

Breathalyzers use a formula to calculate the amount of alcohol present in the blood rather than in the breath. They use a formula based on the average ratio of alcohol in the breath to alcohol in the blood. This “partition ratio” is 1:2100, which means that for any normal person, there will be 2100 units of alcohol in the blood for every unit measured by the breathalyzer in the breath. This means that the amount of alcohol detected in the suspect’s breath sample is multiplied by 2100 to give the blood alcohol level.

External Factors affecting Breathalyzer results

The above formula works well if the breath sample comes directly from the lungs, but if there is even a tiny amount of alcohol present in the suspects mouth, the results will be significantly magnified than the actual results.

Alcohol can be present in the mouth for a number of reasons. Also known as “mouth alcohol”, it can trick the machine to mistakenly apply the partition ratio and multiply the results, giving higher BAC results. Mouth alcohol is one which is not absorbed through the stomach and intestines and passed through the blood to the lungs. A common cause of mouth alcohol is recent drinking. If you happen to take a drink just before getting behind the wheel and are stopped by a police officer a few minutes later who asks you to submit to a breath test, the results will be present, even if your intestines have not started to absorb alcohol.

Use of breath fresheners and certain over the counter medications also affect breath test results. Listerine mouthwash, Altoids or spearmint chewing gum, cough medicines such as NyQuil all contain alcohol which can affect the test results. People who have dental caps, bridges or those who use dentures may also show a higher reading when asked to submit to a breath test. This is because bridges and dentures can capture alcohol in a crevice which may be blown out by breath.

Even simple body functions such as a belch, hiccups, burps or even vomit can affect test results. These actions can bring the vapors of alcohol from the stomach back up to the throat or mouth, giving a higher reading on the breathalyzer. People suffering from GERD (Gastroesophageal reflux disease) also give a higher reading as alcohol can travel up from gastric distress.

If you or a loved one has been charged with DUI in the state of Florida, you need to hire a DUI defense attorney immediately. Your lawyer will make sure that your rights as a citizen are protected and will work to have the charges against you dropped. Your lawyer will also try to find loopholes in your case to use in court in your favor.

Author: Amir Ladan
A former assistant state attorney for Orange/Osceola Counties, Amir has handled thousands of cases and dozens of trials, ranging from DUI and traffic offenses to murder, in both adult and juvenile court.

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