In the United States, the most common definition of binge drinking was created by the National Institute of Alcohol Abuse and Alcoholism in 2009. It says that binge drinking is a pattern of drinking alcohol that brings a person's blood alcohol content (BAC) to 0.08 or more. Blood alcohol content is the percentage of ethanol in the person's blood. (In the United States, a BAC of 0.08 means a person is legally drunk.) This means that a person would be binge drinking if: