The effect of swallowing or rinsing alcohol solution on the mouth alcohol effect and slope detection of the intoxilyzer 5000.

Nine female and 21 male alcohol-free subjects introduced 10 mL of diluted gin (20% v/v alcohol) into their mouths under two conditions. The subjects either rinsed the alcohol for 10 s and then expectorated or immediately swallowed. They then provided breath samples into an Intoxilyzer 5000 at 5 and 10 min postadministration for both conditions. The mean Intoxilyzer results plus or minus one standard deviation (n = 30) were 0.091+/-0.051; 0.036+/-0.027; 0.014+/-0.011, and 0.004+/-0.006 g/210 L for 5 min after rinsing, 5 min after swallowing, 10 min after rinsing, and 10 min after swallowing, respectively. The percentages of times that mouth alcohol was correctly detected by the Intoxilyzer 5000 were 90%, 66%, 62% and 30% for these conditions, respectively. Ten minutes after the introduction of alcohol into the mouth, 63% of the Intoxilyzer results were > 0.010 g/210L after rinsing compared with only 7% after swallowing. The mouth alcohol effect is greater for rinsing than for swallowing alcohol.