Blood Alcohol Concentration

Blood Alcohol Concentration (BAC)

  • BAC is the amount of alcohol present in your body when you drink alcohol. 
  • Your BAC level indicates the amount of alcohol traveling to your brain.
  • BAC charts are used to estimate your blood alcohol level according to your sex, weight, and number of drinks you consume.
  • Researchers have found a BAC between .02%-.06% is a sensible range for moderate drinking. For a 160 pound man, that's 1 to 3 drinks; for a 140 pound woman, that's 1 to 2 drinks. "One drink" is usually equal to 1.25 oz. of 80 proof liquor, 12 oz. of regular beer, or 5 oz. of table wine.
  • Having a high tolerance to alcohol is not necessarily beneficial. It costs more and it increases the likelihood of physical dependency and long-term medical problems such as cirrhosis of the liver, pancreatitis, and high blood pressure.

Facts about BAC

  • A blood alcohol level of .05% is considered low risk for problems. At this level you are more likely to experience the euphoric effects of alcohol, feeling relaxed and sociable.
  • All states have set .08% BAC as the legal limit for Driving Under the Influence.
  • A blood alcohol level of .12% and over is considered high risk for problems such as blurred vision, slurred speech, difficulty with coordination, balance, and decision making.
  • With a blood alcohol level of .10% or higher, a person is at risk for having a blackout. Blackouts include intoxication to the point of memory loss.
  • BAC is also influenced by variables such as how much food is in your stomach, where you are in your hormone cycle if you are a woman, and the rate of your metabolism.
  • Your mood and behavior while under the influence of alcohol are related to the BAC reached after drinking. Your mood prior to drinking and your expectations of what will happen while you are drinking are both factors affecting your BAC.
  • Tolerance means it takes increasing amounts of alcohol to produce the same effect. Many students think this is beneficial, but it is not for a few reasons. The more you can drink, the more money you spend and the higher your risk for having serious medical problems.

Tips for Moderate Drinking

  • Pace your drinks throughout a span of hours.
  • Alternate with water or a non-alcoholic drink so your BAC doesn't rise quickly over a short period of time.
  • Eat before you drink. It will slow down the metabolization of alcohol in your body.
  • Keep track of how much you are drinking and what size drinks you are consuming.
  • Do not take aspirin, ibuprofen, or acetaminophen before you drink because it thins your blood and your BAC will rise much faster. Mixing these medications with alcohol can also can damage your liver.
  • Do not mix alcohol with medication. It can cause an allergic or toxic reaction in the body. Alcohol also can reduce the effectiveness of antibiotics and over-the-counter medications.

Women and BAC

  • Women can absorb alcohol into the bloodstream faster than men.
  • Women have less body water, so a woman gets a higher blood alcohol concentration compared to a man of similar weight.
  • Birth control and other medications with estrogen increase intoxication in women. The highest BAC levels were achieved during premenstrual time and ovulation.
  • Women have reduced activity of an enzyme called alcohol dehydrogenase that helps to metabolize alcohol in the stomach. Women have an average of 25% less of this enzyme than men.