In California, it is illegal to drive with a BAC of 0.08 or more. Commercial drivers face even stricter standards and may be charged with DUI if their BAC is 0.04 or higher.
For those younger than 21, California has two laws governing drunk driving. People under 21 may face DUI charges under Vehicle Code 23136 (California’s Zero Tolerance Law) if they are found to be driving with a BAC of 0.01 or more. People under 21 may also face charges under Vehicle Code 23140 if they are found to be driving with a BAC of 0.05 or more.