At what BAC level is a person at a high risk of vomiting and unable to drive?

A person is typically considered to be at a high risk of vomiting and significantly impaired at a blood alcohol concentration (BAC) of .15. At this level, an individual’s coordination, judgment, and reflexes are notably compromised, leading to a greater likelihood of negative physical reactions, including vomiting. This level of impairment also indicates that the person's ability to operate a vehicle is drastically reduced, making them a danger on the road.

As the BAC increases, so do the effects of alcohol—slurred speech, motor skill difficulties, and an increased risk of more serious consequences such as blackouts or loss of consciousness. While levels below .15, like .12, may present some degree of impairment, they do not typically carry the same high risk of severe physical reactions. Higher BAC levels such as .18 and .20 indicate even greater degrees of impairment and risk, but the threshold where vomiting and a significant inability to drive become prevalent is recognized at the .15 level.