To determine BAC, which personal attribute must be known?

To determine BAC, which personal attribute must be known?

• A. Weight
• B. Height
• C. Eye Color
• D. Hair Length

Answer: (A)

Knowing how alcohol distributes in the body is what drives BAC estimates. The key factor here is body water and blood volume, which are related to body weight. With the same amount of alcohol, a heavier person has more body water and a larger blood volume, so the alcohol becomes more diluted and the BAC is lower. Lighter people have less body water, so their BAC rises higher for the same amount of alcohol. Height, eye color, and hair length don’t affect how alcohol is absorbed or distributed, so they aren’t used to determine BAC. Therefore, weight is the personal attribute needed to estimate BAC.

Knowing how alcohol distributes in the body is what drives BAC estimates. The key factor here is body water and blood volume, which are related to body weight. With the same amount of alcohol, a heavier person has more body water and a larger blood volume, so the alcohol becomes more diluted and the BAC is lower. Lighter people have less body water, so their BAC rises higher for the same amount of alcohol. Height, eye color, and hair length don’t affect how alcohol is absorbed or distributed, so they aren’t used to determine BAC. Therefore, weight is the personal attribute needed to estimate BAC.