Alcohol is most quickly absorbed by the small intestine. The longer alcohol stays in the stomach, the slower it is absorbed and the slower it affects the body. Food prevents alcohol from passing quickly into your small intestine. When there is food in your stomach before drinking , alcohol is absorbed more slowly.
6-8 hours sounds like a good number, assuming you didn’t get completely hammered the night before . It takes 1 hrs to get one drink processed and removed from your body. so if you have 6 beers with the guys, in 6 hours you should be good. if you have 12 beers with the guys, 12 hours you should be good.
A very approximate guide would be to give yourself an hour per unit of alcohol before driving. For example, if you had a small (125ml) glass of wine worth 2.8 units, you should wait for about three hours before getting behind the wheel.
So the answer to the question, How long after you stop drinking can you pass an ignition interlock device test ? is anywhere from 12 to 24 hours after your last drink . So really, you shouldn’t plan to drive unless it’s been at least 12 hours since your last drink .
Generally, a breathalyzer test can test positive for alcohol for up to 12 hours after consuming one alcoholic drink. The average urine test can also detect alcohol 12-48 hours later. If your BAC is 0.08, it will take approximately 5 hours to metabolize the alcohol completely before you can become “sober” again.