Final answer:
In Alabama, the legal BAC limit for those under 21 is .02%. This stricter standard compared to the 0.08% limit for those 21 and over is intended to deter underage drinking and driving.
Step-by-step explanation:
The legal limit of alcohol for someone under 21 in the state of Alabama is .02%BAC (Blood Alcohol Concentration). The National Minimum Drinking Age Act of 1984 requires states to have minimum drinking age laws, and those under the age of 21 are not allowed to drive with a BAC higher than .02%. This is a lower threshold compared to the legal limit for those 21 and over, which is often at 0.08% BAC. Alcohol affects individuals differently, but the law around the permissible blood alcohol level is intended to prevent alcohol intoxication and thereby reduce the risk of accidents on the road.