- 10% of the ingested ethanol is eliminated unchanged in the urine, exhaled air, sweat, saliva, tears and milk.
- Although relatively negligible, this elimination is sufficient to detect the recent intake of alcoholic beverages by the search for ethanol in exhaled air (rate in alveolar air / blood concentration = 1/2100) or in the urine ( rate in urine / blood concentration = 1.3).