Seven subjects participated in a two-part study to evaluate mouth alcohol dissipation in alcohol positive subjects. In part one, subjects rinsed their mouths with a vodka solution and were breath tested after 1, 2, 3, 4, and 5 min intervals. On average, breath alcohol concentration (BrAC) decreased 20.4% (range 3.2-47.9%) between 1 and 2 min after rinsing. In part two of the study, multiple breath tests were administered after rinsing once with the vodka solution. The BrAC decreased more than 0.020 g/210 L between the first and second tests for all subjects (average 0.095 g/210 L, range 0.021-0.162 g/210 L). The average time for subjects to reach their unbiased BrAC was 9.35 min (range 4-13 min) after rinsing. This study reaffirms the need for duplicate breath testing and confirms that the minimum of a 15-min observation period is sufficient for mouth alcohol to dissipate in alcohol positive subjects.
© 2011 American Academy of Forensic Sciences.