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How Does Blood Alcohol Concentration (BAC) Work

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What You Should Know about Blood Alcohol Concentration (BAC)

Are you one of those people who think you can have a few drinks and still drive?

Two vodka drinks and a glass of wine. Will that take you over the limit?

In the U.S., it is generally illegal for adults to drive with a BAC at or above .08%, which represents the percentage of alcohol in the bloodstream. In December 2018, Utah became the first state to lower the legal limit from .08% to .05%. For drivers under 21, .02 % or any traces of alcohol in the blood is illegal.

Even if .08% is down from .15%, which it used to be at one time, some experts still consider the general limit of .08% too high.

Much of the world sets stricter limits. It’s .02% in China, .03% in most of India and .05% in many European countries.

And remember, a driver’s reaction time starts to slow at a much lower BAC. Even if you are below the legal limit, you can get a ticket if your driving is affected by alcohol or drugs, or both.


How BAC Affects You

How does BAC affect the individual?

One of the most important factors is how fast the alcohol is consumed, says Dr. Samir Zakhari, director of the division of metabolism and health effects at the National Institute of Alcohol Abuse and Alcoholism. The liver can only break down the alcohol at the rate of about one drink per hour. Drinking more than that amount, or the same amount faster, will overwhelm the liver. The excess alcohol goes into the bloodstream and every other organ in the body, including the brain.

Once the alcohol is in your blood it is important to remember that only time can unwind the effects (this is a common question on DMV tests). Meaning, drinking coffee, having a shower, talking a walk or splashing cold water on your face may make you feel better, but it will not change your BAC.

Only time can sober you up -  Photo by Skitterphoto from Pexels

Eating along with drinking causes the alcohol to be absorbed more slowly. But what you eat along with the alcohol doesn’t matter very much in terms of BAC.

You should also know that body fat has some effect on your BAC. When two people weigh the same, the percentage of body fat will make a difference.

Drinkers who think they can tell when they’ve had enough are very often wrong. But how alcohol affects people is highly individual, with a number of factors in the mix. The best advice is always not to drink at all if you’re driving. Or let someone who has not been drinking to drive you home.

Alcohol is a depressant, not a stimulant. This means that alcohol slows your reactions and dulls your judgment.

Source: Testing the Limits of Tipsy

Cover Photo courtesy of Dreamstime

About Mark
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  1. It is important to know that sober-up pills or hangover pills don’t work either. Might make you feel better. But the alcohol is still there. A waste of money!

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