The Legal Alcohol Limit in California: Drunk Driving Laws & Penalties

According to California Vehicle Code (VC) Section 23152, the legal alcohol limit for an adult 21 or over is a blood alcohol concentration (BAC) of 0.08 percent. According to VC Section 23136, the legal alcohol limit for a person under the age of 21 is a BAC of 0.01 percent. According to VC Section 23154, the legal alcohol limit for a person of any age on a DUI probation is 0.01 percent.

The legal alcohol limit for an adult 21 or over is a blood alcohol concentration (BAC) of 0.08 percent. The legal alcohol limit for a person under the age of 21 is a BAC of 0.01 percent and the legal alcohol limit for a person of any age on a DUI probation is 0.01 percent.

VC Section 23152 states the legal alcohol limit for a person in any vehicle requiring a commercial driver’s license (CDL) is 0.04 percent. According to the California Department of Motor Vehicle's Commercial Driver Handbook, this is true whether or not the driver has been issued a CDL.

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The penalties for a DUI depend on the number of DUIs the offender has committed in a 10-year period, the offender’s age, and aggravating or mitigating factors for the DUI. According to the Superior Court of California, Alameda County, for adults, DUIs are generally penalized with a fine, jail time, driver’s license suspension, DUI school, installation of an ignition interlock device (IID) and probation. According to VC Section 23152 and California Penal Code Section 19, a first, second or third DUI is typically charged as a misdemeanor.

Fines range from $390 to $1,000 plus penalty assessments, county jail time from 48 hours to one year, driver’s license suspension from six months to three years, DUI school from three months to 30 months, IID installation from six months to two years and probation from three to five years of unsupervised probation.

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According to VC Section 23153 and VC Section 23540, a fourth or subsequent DUI arrest is usually charged as a felony. Fines range from $390 to $1,000 plus penalty assessments and state prison time from two to three years. The driver’s license revocation lasts for four years, the IID requirement for three years, and the offender will serve between three and five years of supervised probation.

According to the California Legislative Analyst's Office, there is a monthly cost for supervised probation. There can be additional penalties for misdemeanor and felony DUI charges, including required attendance at a victim impact panel (VIP), tow, storage and impound fees for the driver’s vehicle, increased insurance costs, attorney’s fees and more.

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A minor, defined as a person under 18, is considered differently by the law than a young adult between 18 and 20. The penalties outlined here cover a first-time DUI conviction. If a minor or young adult under 21 commits a second DUI, the penalties increase.

According to the DMV Driver Handbook, the Judicial Branch of California, and VC Section 23136, the penalties for a minor found by the juvenile delinquency court to have committed an act of driving under the influence include an administrative driver’s license suspension imposed by the DMV for one year or until the individual turns 18, whichever is longer. The penalties for a young adult between the ages of 18 and 20 includes a one-year driver’s license suspension. If a minor or young adult between 18 and 20 has a BAC over 0.05 percent, they will be required to pay a $100 fine and attend an alcohol education program.

A young adult between 18 and 20 or a minor with a BAC of 0.08 can be charged with an adult DUI. The penalties for a first offense include a one-year license suspension by the criminal court; a fine of $390 to $1,000 plus penalty assessments; unsupervised probation for three to five years; juvenile probation for a minor; and jail time up to six months. If the individual is a minor, the penalty may include time in a youth correctional facility for up to six months.

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According to the California Department of Motor Vehicles California Driver Handbook, blood alcohol concentration (BAC) is the percentage by weight of alcohol in an individual’s blood. If a motorist’s BAC is higher than the legal limit, it is illegal for them to drive.

Stanford Children's Health indicates how an individual’s sex, age and weight affects how much alcohol they can consume to reach the BAC limit. Women and individuals who weigh less tend to see their BAC rise more quickly. Older people take longer to metabolize alcohol.

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In California, a BAC that is much higher than the legal limit is a sentence enhancement. According to VC Section 23578 and VC Section 23140, an excessive BAC can increase the penalties for a DUI. VC Section 23538 states that there are two thresholds for excessive blood alcohol, a BAC between 0.15 percent but less than 0.20 percent, and a BAC of 0.20 percent or more.

An excessive BAC can result in a longer period of driver’s license suspension, a longer jail sentence, higher fines, a longer DUI school and more.

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Breathalyzer tests can be accurate if the equipment is properly calibrated. This means that results from the device are checked against a known alcohol standard. Car & Driver and The New York Times note that breathalyzer tests are unreliable if the equipment is not correctly calibrated. Breathalyzer results can be altered if officials set up the device with stale or home-brewed chemical solutions that throw readings off or use machines with animals like rats nesting inside.

The software in breathalyzers can contain programming mistakes. Substances that contain minute amounts of alcohol, such as hand sanitizer, toothpaste, breath mints and mouthwash, can also throw the machine off. Asking for records of how a breathalyzer was calibrated, maintained, stored and programmed can be critical in a DUI case.

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A preliminary alcohol screening test, or PAS test, is given to a driver suspected of driving under the influence. The PAS test is a roadside test that a law enforcement officer administers on a breathalyzer or similar device. It determines how much alcohol is in the driver’s breath.

The device then converts the amount of alcohol in the breath to an equivalent amount of alcohol in the blood. If the driver’s breath contains any alcohol, they will not be allowed to drive.

A post-arrest DUI chemical test is typically either a DUI breath test or a DUI blood test. According to the DMV Driver Handbook, such a test can also be a urine test. A chemical test is usually administered as soon as possible after arrest.

A breath test is faster and measures the amount of alcohol in deep lung air. A device then converts this into an approximately similar BAC. A blood test, which is considered to be more accurate than a breath test, measures the amount of alcohol in the bloodstream.

According to VC Section 23136, California’s zero tolerance law means that the maximum legal BAC for drivers under 21 is 0.01 percent. According to California Vehicle Code Section 23152(b), the term “per se” refers to the concept that a driver with a BAC of 0.08 percent or higher has a driving ability that is impaired due to alcohol consumption.

According to VC Section 23612, California has an implied consent law that makes it mandatory for any driver who has been lawfully arrested for DUI to submit to a blood or breath test to determine their BAC level.

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An individual who has failed a chemical test and is accused of a DUI offense should contact a DUI lawyer. The defense attorney will be able to request materials to determine whether the arrest was lawful and the device used for the chemical test was properly calibrated. These data will allow the DUI attorney to see if there is a way to challenge the arrest and the results of the chemical test.

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