The Blood Alcohol Test is used to determine the presence and amount of ethyl alcohol (drinking alcohol) in the donor’s blood. The detection window for this test is dependent upon the amount of alcohol ingested, as well as other factors including the sex and metabolism rate of the individual. This test should only be used if you are interested in assessing if the individual tested is under the influence of alcohol. Once a person is not under its influence, alcohol is generally not detected in the bloodstream and other tests would be more appropriate. A small sample of blood will be sent to the laboratory for analysis.