Middlesex Legal Defense Update: Cigarette Smoking Might Skew Jersey Breathalyzer Results for DWI Arrestees

Accused drunk drivers in Bergen, Union, Monmouth and Sussex County may be surprised to hear that the breath testing devices used by state and local police agencies can be affected by the chemicals known to be present in cigarette smoke. Understanding this technical issue can sometimes help a DWI defendant to better prepare for his defense against a charge of driving while intoxicated in the Garden State.

As New Jersey drunken driving defense lawyers, I and my staff have a deep understanding of the operational and maintenance aspects of breath testing machines — such as the Alcotest device — and how this equipment might record falsely high blood-alcohol content (BAC) reading that in no way represents a driver’s actual state impairment or sobriety.

As DWI defense attorneys, my firm has represented numerous motorists who were accused of driving under the influence of alcohol, yet were in reality not legally drunk at the time. Many times the state’s primary evidence comes directly from the breathalyzer machine.

A good many drivers, when confronted with a DWI or DUI arrest, will no doubt wonder what factors — aside from the actual consumption of beer, wine or hard liquor — will influence the measurement of their blood-alcohol content (BAC) via an Alcotest machine or other breath testing device. Certainly, as New Jersey drunk driving defense lawyers, I and my colleagues understand the law in this state quite well. Sadly, however, the science that backs up the state’s conviction of an alleged drunken driver may not always be totally reliable.

Whether a motorist submits to a breath test at police headquarters or on-site at a mobile DWI unit, the machines used to determine a driver’s BAC level are very similar in nature. Contrary to popular believe, a breathalyzer device does not actually measure the blood for alcohol content, it actually analyzes the subjects breath for trace amounts of certain chemicals, specifically those compounds containing the methyl group of molecules.

Based on this methyl measurement, the machine then produces a final blood-alcohol reading translated into a percentage of alcohol to blood in that individual’s body. It is this BAC reading that the local prosecutor’s office typically uses to justify any charges of drunken driving and to secure a conviction.

It is important to understand, however, that one of the weaknesses of this kind of measuring system relies on the assumption that any methyl molecule detected in the suspect’s breath sample comes only from alcohol. In the most simplistic scenario, this might be a valid assumption; however, there are many other sources of methyl molecules in nature.

Unfortunately, this method of BAC measurement — used by breath test devices such as the Alcotest machine, which has been used extensively across New Jersey — cannot differentiate between methyl molecules from alcohol or from that of other substances.

Because of the simple fact that the methyl group occurs elsewhere in nature, it is important to realize when and where a false BAC reading might be encountered. In one group of drivers, there is a distinct possibility that a breathalyzer machine could wrongly implicate a person as being drunk behind the wheel. Smokers are one such group that run the risk of being falsely accused of DWI.

For those people who don’t have a background in chemistry, the following brief explanation might be instructive. Acetaldehyde is a compound produced in small quantities by the human liver during the body’s natural breakdown of alcohol. What has been scientifically established by some researchers is that acetaldehyde is found in the lungs of smokers, in typically greater concentrations than that of non-smokers.

To put it simply, smokers may have a greater chance of registering an erroneously high BAC reading when compared to that of non-smokers; this could mean that a driver who smokes might be stopped for a traffic infraction and through a series of steps find him or herself providing a breath sample, the result of which could trigger a charge of DWI. This is certainly something to keep in mind for all those who enjoy tobacco on a fairly regular basis.