Lack of Effect of Over-the-Counter Oral Care Strips on a Forensic Breath Alcohol Testing Device

There have been a considerable number of cases litigating the validity of the forensic breath alcohol test and the potentials for a false positive ethanol reading. Recently, a claim asserted that the prior use of an over-the-counter (OTC) “oral care strip” normally used to suppress halitosis of the oral cavity, produced a false positive result when a subject was given a breath alcohol test during a criminal investigation. Since the effects of oral care strips on breath alcohol testing had not been previously investigated, we undertook this study. Several brands of OTC oral care strips were tested on two separate breath alcohol analyzers: the Intoxilyzer 8000 and Intoxilyzer 5000. Test subjects consisted of two male and two female volunteers, one of which had a set of partial dentures. Results obtained from the breath testing instruments after the subjects used the oral care strips showed no false positives for ethanol. We conclude that the use of OTC oral care strips prior to testing on a forensic breath alcohol analyzer does not result in a false positive ethanol reading. Background The reliability of forensic breath alcohol tests to accurately determine breath alcohol content when an additional substance was introduced into the oral cavity has been tested both in and out of the court system. Investigations into the validity of false positive claims has led to the independent testing of a variety of substances introduced into the oral cavity such as blood, asthma inhalers, and oromucosal sprays for their effect on readings of breath alcohol content. Over-the counter (OTC) “oral care or breath strips” are starch based films that dissolve quickly in the mouth releasing breath freshening substances such as mint and menthol, and are used by consumers to minimize strong breath odors. Recently, forensic breath alcohol test results were questioned in a criminal prosecution case for driving under the influence of alcohol (DUI) in Broward County, Florida, USA due to the prior use of an OTC “oral care strip” by the defendant. Objectives To determine if recent use of an “oral care strip” can falsely increase the alcohol level calculated by an evidential breath alcohol analyzer in a drinking driver.