The study sample included 15 male and 15 female alcohol-free subjects who consumed a mouthful of beer (5 percent alcohol) from a beer bottle. Intoxilyzer 5000C tests were conducted 5 and 10 minutes after the consumption of beer. The volume of beer consumed by male subjects was significantly greater than the volume consumed by female subjects, and subjects were allowed to talk during the experiment to simulate social conditions. Results demonstrated a positive breath alcohol concentration (BrAC) occurred in 13 subjects (43 percent) 5 minutes after the consumption of beer. Ten minutes after the consumption of beer, measured BrAC's in all subjects were zero. There was no apparent correlation between the BrAC and the amount of beer consumed. The Intoxilyzer 5000C did not identify any of the low BrAC's as "mouth alcohol." The authors conclude that the duration of a significant mouth alcohol effect for consuming beer under social conditions is less than the usual 15-20 minutes and that this decreased deprivation time may facilitate more rapid breath alcohol screening tests in the field. 13 references and 2 tables