What is the legal blood alcohol concentration (BAC) limit for drivers over 21 in California?

The legal blood alcohol concentration (BAC) limit for drivers over 21 in California is 0.08%. This means that if a driver's BAC is measured at 0.08% or higher, they are considered legally impaired and can be charged with driving under the influence (DUI). This standard is established to help ensure road safety, as higher levels of alcohol can significantly affect driving abilities, increasing the risk of accidents.

It's important to understand that this limit is specifically for drivers aged 21 and older. For drivers under 21 and for commercial vehicle operators, the legal limits are lower, reflecting stricter regulations for these groups. The choice of 0.08% is widely adopted across many states in the U.S., promoting consistency and clarity regarding allowable limits for alcohol consumption while driving.

While lower BAC levels, such as 0.05% or 0.10%, may seem like they could be reasonable limits, they do not reflect California's established legal standard for impairment among adult drivers, which is set definitively at 0.08%.