According to Science, Odor of Alcohol Not a Reliable Indicator of Intoxication

In nearly every drunk driving arrest, the police officer’s narrative report will indicate the observation of “strong odor of intoxicants.” As with all the facts, it will ultimately be up to a jury to decide the meaning of this observation, and to “weigh” it along with all the evidence in a DUI trial.

Before the case even goes to trial, the odor of intoxicating beverages can also be used by a judge in determining if there was probable cause to make the arrest, to begin with. All of this begs the question; is the odor of intoxicants a reliable indicator of anything, much less a reliable indicator of drunk driving? According to scienctific research, the answer is a resounding no!

The odor of an alcoholic beverage is, as an indicia of intoxication, nearly meaningless because “…even under optimum laboratory conditions, breath odor detection is unreliable…” The results also cannot be used to “guess” the driver’s bodily alcohol level or quantify consumed. Both statements appear in the study entitled Police Officers’ Detection Of Breath Odors From Alcohol Ingestion by Herbert Moskowitz, Marcelline Burns, and Susan Ferguson that appeared in Accident Analysis Prevention 31 (1999) 175-180.

The odor of an alcoholic beverage is primarily due to congeners. Congeners include fusel oils, which are a mixture of thick evaporative liquids produced in minute quantities as part of the fermentation process. Fusel oils are alcohols, and there are more than 45 different alcohols that can be congeners. They are mostly aliphatic alcohols. They are not ethyl alcohol, but they would be detected on gas chromatography, the type of testing used by the Michigan State Police Toxicology Lab to evaluate blood drawn as part of a DUI investigation.

Additionally, other volatile organic compounds other than ethanol exhibit Infrared (IR) absorption bands that overlap a 9.5 µm wavelength. This is significant because many alcohol breath testers used in drunk driving investigations absorb at 9.5 µm on infrared (IR) spectroscopy. In other words, fusel oils can be mistaken as actual beverage alcohol and falsely inflate a breath test reading. See, e.g., Dominic A. Labianca, How Specific for Ethanol is Breath-alcohol Analysis Based on Absorption of I.R. Radiation at 9.5 Micrometers? , and Journal of Analytical Toxicology, vol. 16, November/December 1992, pgs. 404-405.

As pointed out above, but worth repeating due to the prevalence of this belief among law enforcement, the odor of alcohol on the breath is only qualitative, not quantitative. The presence of such an odor does not equate to intoxication. Instead, it may only indicate the presence of gastroesophageal reflux, also known as heartburn or GERD.

If you were arrested in Michigan for DUI and the police claim as part of their investigation that they observed a strong odor of intoxicants, then be sure to print this article show it to your lawyer. Hopefully, your lawyer will know how to use this information to your advantage. Otherwise, if it remains unchallenged, this “evidence” can help bolster the prosecutor’s claim that your DUI arrest was valid or help them persuade a jury to conclude that the prosecutor has met their burden of proof to find you guilty. Neither of these things should ever happen based on evidence that is so clearly scientifically unreliable. Call today to start working with a lawyer on your case.

Posted In:
Published on:
Updated:

Comments are closed.

Contact Information