Final answer:
In California, the legal BAC limit for drivers 21 and older is 0.08%. This threshold is used to determine DUI and aligns with federal mandates set by the National Minimum Drinking Age Act of 1984.
The body metabolizes alcohol at a consistent rate, with variations based on individual factors.
Step-by-step explanation:
In California, drivers aged 21 and older are presumed to be driving under the influence (DUI) with a blood alcohol concentration (BAC) of at least 0.08%. This legal limit is consistent with the majority of other US states, which define legal intoxication at a BAC of 0.08%.
Alcohol metabolism in the human body breaks down consumed alcohol at a rate of about 0.015% per hour. However, factors such as age, sex, body weight, and the rate of alcohol consumption can impact an individual's BAC level and the effects of alcohol. It has been demonstrated that higher BAC levels can cause acute intoxication (0.20% BAC), unconsciousness (around 0.30% BAC), and even death (around 0.50% BAC).
Pursuant to the National Minimum Drinking Age Act of 1984, penalties for states not raising the minimum drinking age to twenty-one include a reduction in federal highway funds, influencing all states to comply with setting the legal BAC limit to 0.08% for drivers aged 21 and over.