Blood Alcohol Concentration (BAC) refers to the percent of alcohol (ethyl alcohol or ethanol) in a person’s bloodstream and is usually determined by a breathalyzer test or a blood test when the police suspect a driver of being intoxicated. For example, a BAC of .10% means that the person’s blood supply contains one part alcohol for every 1,000 parts blood.

In most states a driver is considered legally intoxicated if their BAC is .08 or higher. This BAC level is generally prescribed by a state statute (a law enacted by the state legislature) and creates a presumption of intoxication—also known as per se BAC because it is intoxication by definition. In Utah, the per se BAC level is .05.

Most states have a zero-tolerance BAC level of .02 for drivers under the legal drinking age (usually 21) that will result in a DUI/DWI charge. And most states also have an enhanced penalty or aggravated DUI/DWI charge for drivers whose BAC is .15 or higher—with a few states placing this aggravated or enhanced-penalty DUI/DWI BAC level at .16 to .20.

In Georgia, the Blood Alcohol Concentration (BAC) limit for drivers is consistent with the majority of states, where a driver is considered legally intoxicated if their BAC is .08% or higher. This is the per se BAC level, meaning that a driver with a BAC at or above this threshold is presumed to be driving under the influence (DUI) by law. For drivers under the age of 21, Georgia enforces a zero-tolerance policy with a BAC limit of .02%, in line with the zero-tolerance laws aimed at underage drinking and driving. This means that any detectable amount of alcohol can result in a DUI charge for an underage driver. Additionally, Georgia imposes more severe penalties for drivers who are caught with a BAC of .15% or higher, which is considered an aggravated level of intoxication. These enhanced penalties can include longer jail time, higher fines, and more severe license sanctions.