What is "blood alcohol level"?
Blood alcohol concentration (BAC) is a term used to describe the level of alcohol in the bloodstream of a person arrested for drunk driving. It is used in court as evidence of that offense. The most common method of determining BAC is through a breath test, although blood and urine testing is done in some instances. If the level is found to be at or over .08, the test results can establish a presumption of impairment.