Dr. Bill, I am a male, 165lbs and 6'0. On Saturday night I drank a 750ml bottle of 80proof vodka and four beers, starting at 5pm and ending at midnight. The next day I blew .00 with a breathalyzer at 1030am. At 530pm I had to give a urine sample for ethanol testing, not EtG. Between 1030am and 530pm I flushed my system with excessive water, around six bottles, and voided around six to seven times. My question, (other than the obvious will I pass?) is about the correlation between UAC and BAC. If my BAC was .00 at, was my UAC around 00 after I had voided once or twice?

Thanks.

UAC can be correlated to BAC. However the only relevant issue is time from BAC=0 to urine and that is about 20 minutes. To be entirely safe allow two hours*. Then it is simply a process of clearance by urination. In short, urine will provide only a slightly longer detection period than a blood test.

While it is probably inapplicable to your case, another factor in UEtOH testing is level of detection. Usually this test only detects the presence of alcohol at or above .04 (BAC equiv) and none below .02. (both figures +/- 25%)

UEtOH testing has little value except in very short term suspicion of drinking or to confirm another test, such as breath or blood tests.

*Breath analyzers convert BAC at a ratio between 21-2300:1 and also have a range +/- range of accuracy on top of that. By extending BAC=0 by two hours that is more than enough to account for any variance between actual BAC and BrAC reading.