Roadside breath test devices may give inaccurate results

Although officers in North Carolina use roadside breath tests to determine alcohol toxicity, studies show that these devices may give inaccurate results.

When law enforcement officers pull motorists over on suspicion of driving while impaired in North Carolina, they often ask drivers to submit to a breath test. Officers use these roadside tests to tell whether a driver is intoxicated. Yet, many studies show that the results obtained from breath test devices may not always be accurate. In some cases, unreliable breath test readings may cause an innocent person to be charged and even convicted of a DUI.

Breath tests vs. blood tests

Breath test devices calculate a driver's blood alcohol content level indirectly by measuring how much ethyl alcohol is present in his or her breath sample. Blood tests, on the other hand, calculate the blood alcohol content directly, and are therefore more accurate. Since blood tests are not often feasible in a roadside situation, officers use breath test devices to determine whether a person is driving with a BAC over the legal limit of 0.08 percent. The readings may be used as evidence in certain situations.

The problem with breath tests

There are many factors that contribute to an inaccurate breath test device reading. Studies conducted by the State University of New York at Potsdam found that breath analyzers detect more than simply the presence of ethyl alcohol. Many devices also pick up methyl alcohol groups which are similar in structure, but are found in a myriad of substances, including human saliva. The study also found that breath test results may be influenced by the presence of food, vomit or blood in a person's mouth. Other factors, including electrical interference from police radios, lingering tobacco smoke and whether the driver has been exposed to paint or gasoline fumes can cause an inflated BAC reading on a breath test.

Operator error is another problem with breath test machines. Not only is it crucial that the officer understands how to properly use the device, but the machine must be calibrated regularly in order to maximize the accuracy of the results. Breath test devices should be calibrated to account for the ambient temperature, as well as the humidity present in the environment, according to the study.

Legal assistance may be necessary

A DUI conviction in North Carolina can make it hard to find employment in certain industries, receive financing or even qualify for student loans. If you have been arrested and charged with a DUI in North Carolina, you may want to consider contacting a defense attorney. Whether you were given a roadside breath test or another type of field sobriety test, an attorney may be able to help you formulate a strong defense for your case.

Keywords: breath test, DUI, drunk driving, arrest