The ABC's of BAC: Understanding Blood Alcohol Concentration and Alcohol Impairment

Q: What is “BAC”?

A: The amount of alcohol in a person’s body is measured by the weight of the alcohol in a certain volume of blood. This is called the blood alcohol concentration, or “BAC.”

Alcohol is absorbed directly through the walls of the stomach and the small intestine, goes into the bloodstream, and travels throughout the body and to the brain.

Alcohol is quickly absorbed and can be measured within 30 to 70 minutes after a person has had a drink.

Q: Does the type of alcohol I drink affect my BAC?

A: No! A drink is a drink, is a drink.
A typical drink equals about half an ounce of alcohol (.54 ounces, to be exact). This is the approximate amount of alcohol found in:

• one shot of 80 proof hard alcohol, or
• one 5-ounce glass of wine, or
• one 12-ounce 5% beer.

Q: What affects my BAC?

Gender

Women (typically) have more body fat than men and the alcohol enters the blood stream more quickly so it takes less alcohol for women to reach .08 than it does most men.

Amount of alcohol/How many drinks per hour consumed

It takes the body an hour to process a standard drink. Each drink consumed during an hour adds to the BAC so someone that has 2 standard drinks in one hour will have a higher BAC than someone that has only 1 standard drink in an hour (when comparing two equal people).

Food intake

Food slows the absorption of alcohol so 1 standard drink of alcohol on an empty stomach will have a different effect than the same drink on a full stomach.

Mood/Fatigue

Being overly tired or stressed or being in any extreme mood – happy, sad, angry…will be intensified by alcohol.

Q: What about other medications or drugs?

Many medications intensify the effects of alcohol or the alcohol intensifies the medication’s effects – this can be a dangerous and even deadly combination. For more information on BAC, see the chart below.

How can I "sober up"?

Nothing but time can sober a person up. The body can only process one standard drink per hour-- no matter how much coffee, walking or showering a person does, they will need one hour for each standard drink consumed.

What is alcohol poisoning?

• CAUTION: The body can only process 1 standard drink per hour – consuming more than 1 standard drink per hour may lead to alcohol poisoning. According to Mayo Clinic Staff, symptoms of alcohol poisoning include:
• Confusion, stupor
• Vomiting
• Seizures
• Slow breathing (less than 8 breaths a minute)
• Irregular breathing ( a gap of more than 10 seconds between breaths)
• Blue tinged or pale skin
• Low body temperature
  
• Unconsciousness (passing out)

If a person you are with has any of these signs call for medical help. If they are taking less than 8 breaths per minute or are vomiting uncontrollably call 911 immediately. Never leave an unconscious person alone – their BAC will continue to rise as the alcohol enters the bloodstream, even after they stop drinking.

Q: How will I know I’m impaired, and why should I care?

A: Alcohol steadily decreases a person’s ability to drive a motor vehicle safely. The more you drink, the greater the effect. As with BAC, the signs of impairment differ with the individual.

While the lower stages of alcohol impairment are undetectable to others, the drinker knows vaguely when the “buzz” begins. A person will likely be too impaired to drive before looking – or maybe even feeling – “drunk.”

Every State has passed a law making it illegal to drive with a BAC of .08 or higher. A driver also can be arrested with a BAC below .08 when a law enforcement officer has probable cause, based on the driver’s behavior.

The following chart contains some of the more common symptoms people exhibit at various BAC levels, and the probable effects on driving ability: