Flaws With Breathalyzer Tests and DUI Charges

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Most people consider a breathalyzer reading to be irrefutable evidence when it comes to proving whether or not you were driving while your Blood Alcohol Content (BAC) was elevated past the legal limit. However, as with all equipment, there is still a margin of error and many variables that can adversely affect the readings of a breathalyzer test.

Causes of Errors in BAC Readings

An improperly calibrated breathalyzer can cause the ratio at which the machine calculates the amount of alcohol in your blood to fluctuate as much as 1000 points, causing extremely inaccurate results. General malfunctions such as low batteries or magnetic interference with onboard storage media can also compromise result reports from a breathalyzer unit.

The state of your mouth at the time of your BAC testing also has a huge effect on the readings. Residual alcohol trapped in your mouth within your saliva, food caught in your teeth, or residue on your tongue can all increase your BAC readings. Breathalyzers also detect the methyl part of a molecule present in alcohol – and many other substances. The machine may be detecting other chemical compounds that contain methyl besides liquor. For example, use of an alcohol-inclusive mouthwash has been shown to increase BAC readings.

Another major flaw in the breathalyzer unit is that the breathalyzer assumes the temperature of your mouth is about 93 degrees Fahrenheit. Some studies have shown that individuals arrested for DUI had actual mouth temperatures between 93 and 98 degrees, another variable that can negatively influence the BAC reading. A breathalyzer can only estimate the content of alcohol in your blood, and this estimation is based on the amount in your lungs and breath. Therefore, if you have belched, hiccuped, or vomited within 20 minutes of testing, this may also increase the BAC readings and lead to a DUI arrest when you were driving while below the legal limit.

Your body composition is also an important factor in how your BAC readings are reported. Two people with a 100-pound weight difference can consume the same amount of alcohol in the same period of time, but the lighter person can be affected up to twice as much as the heavier person. Your metabolism also impacts alcohol absorption. Breathalyzers test the level of alcohol as it has been absorbed into the bloodstream, but depending on how fast your metabolism works, it may not have completely absorbed at the time of testing.

Unreliable results can alter court rulings

If your DUI defense attorney can convince a jury that your BAC test was flawed, they’re less likely to consider a guilty verdict. With all the variables that can affect breathalyzer readings, there’s a good chance that any of the issues listed above affected your breathalyzer readings. A good DUI defense lawyer knows what to look for and knows how to question this kind of evidence in court.

With all of these ways the BAC test can be inaccurate or altered, a breathalyzer BAC reading is not always considered to be an accurate indicator of DUI. While some state DUI law does not allow you to deny a breath test when suspected of DUI, a blood test can be used if the person accused is unable to submit to a breath test.

If you trust the breathalyzer and want to know what your BAC reading is before you get behind the wheel there are many products you can purchase at amazon.com.

Product Description

Designed for maximum accuracy - used by hospitals, schools, and law enforcement as an alcohol screening device. The AlcoHAWK Pro is one of the most accurate semiconductor-oxide breathalyzers available. This new model takes a deeper breath sample from subjects and provides more accurate results than similar models. This model is trusted by many professional organizations for employee screening, emergency room care, and roadside testing. The semiconductor sensor accuracy is ±0.01%BAC at 0.10% BAC and is DOT / NHTSA approved as an alcohol screening device. The AlcoHAWK Pro is also 510(k) Certified by the U.S. Food and Drug Administration. The AlcoHAWK Pro now includes innovative FlowCheck technology. An important aspect of breath testing is ensuring that subjects blow a large volume of air through the tester. FlowCheck will verify that enough air has been blown through the AlcoHAWK Pro before displaying a test result. If the FlowCheck engages and recognizes that not enough air was blown, an error message will be displayed and a retest should be performed.