Understanding Blood Alcohol Level

Estimating BAL

Other Factors Impacting BAL and Impairment

Practice Exercises

Answers to Exercises

Reflections

Understanding Blood Alcohol Level

Blood alcohol level (BAL) refers to the ratio of alcohol to blood in the bloodstream. It also accurately reflects the level of alcohol in the entire body. BAL, also known as blood alcohol concentration (BAC), is represented as a percentage. Here’s an analogy which may help you understand what those numbers represent. Picture this—a shelf with 10,000 compartments. Each compartment is filled with a drop of blood. If I replace one drop of blood with one drop of alcohol, the shelf now has a BAL of .01 percent. If I replace two drops of blood with two drops of alcohol, the shelf now has a BAL of .02 percent. If I replace ten drops of blood with ten drops of alcohol, then the shelf has a BAL of .10 percent.

Previously a BAL of .10 percent was considered legally drunk in most states. National legislation in the year 2000 has proposed a national BAL limit of .08 percent—and rightly so. After all, ongoing research continues to indicate a clear, direct relationship between increased BAL and increased risk for automobile crashes, serious injury and death.

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Estimating BAL

To estimate Blood Alcohol Level (also known as Blood Alcohol Concentration - BAC):
- move down the Drink/Weight  Index chart below to the number of drinks and your gender.
(A drink equals a 12 oz. regular beer, 1 oz. shot of 100 proof liquor, 1.5 oz. shot of 80 proof liquor, or 4 oz. glass of regular table wine)

- move across the chart to your weight to arrive at your Drink/Weight Index

- subtract .01% from  the Drink/Weight Index for each hour from the start of
the drinking period to the point in time you want to measure the BAL.

Remember!!! This is only an estimation based on an average metabolic rate. Differences in metabolic rates, gender, types of drinks, food in the stomach etc. can contribute to substantial differences in your Blood Alcohol Levels. Also, there may be slight differences (.01 - .03) between the various BAL Charts that are available to you.

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Other Factors Impacting BAL and Impairment

In addition to the amount of alcohol consumed, the speed at which it is consumed, and your tolerance, here are a number of other factors that will also affect how quickly and to what degree you will get impaired if you choose to drink:

- Food in the stomach will slow the absorption of alcohol into the bloodstream and delay impairment. The type of food ingested (carbohydrate, fat, protein) has not been shown to have a measurable influence on BAL. However, we do know that the larger the meal and the closer the time between eating and drinking, the lower the peak blood alcohol concentration. Studies have shown reductions in peak blood alcohol concentration (as opposed to those of a fasting individual under otherwise similar circumstances) of between 9 percent and 23 percent.

- Alcohol mixed with carbonated beverages such as Coca-Cola or Seven Up will be absorbed more quickly into the bloodstream. This is also true for champagne and wine coolers.

- Women who are pre-menstrual and sometimes those on birth control pills tend to get more impaired more quickly.

- Strong emotions—anger, fear, loneliness—tend to hasten impairment.

- If you are tired, sick or just getting over an illness, you tend to get more impaired more quickly.

- Mixing alcohol with other drugs often leads to increased impairment in a shorter period of time.

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Exercise 1:
John weighs 200 pounds and is 22 years old. He is out at a party and has been drinking shots and beers. He had five shots (1 ounce of 100 proof whiskey) and a twelve ounce bottle of beer after each shot. He has been drinking at the party for three hours. The host suggested he quit drinking alcohol and gives him some coffee to sober him up. After drinking coffee for the next hour, what is his estimated BAL?
Answer

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Exercise 2:
As part of an organization’s initiation ritual, Cindy who weighs 125 pounds is forced to drink screwdrivers containing double shots (1.5 ounce of 80 proof vodka per single shot). She has had seven of these screwdrivers in two hours. Connie has become delirious and her friends place her in a cold shower to sober her up. What is Cindy’s estimated BAL after two hours?
Answer

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Exercise 3:
Ralph brings a six pack of average beer with him for a visit with his friends. They are watching a football game on television which lasts four hours. He finished his six pack while watching the game. After leaving his friend’s house, he is immediately stopped by the police. He is 20 years old and weighs 180 pounds. Will he get a DUI ticket? If he were 21 years old and weighed 200 pounds would he get a DUI ticket?
Answer

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Exercise 4:
Imagine it is 1 o’clock in the morning and you have had enough alcohol to bring you to a BAL of .18. You decide to stop drinking and go to sleep due to an important 9 o’clock class. What would your estimated BAL be when you entered the class at 9 o’clock in the morning?
Answer

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Exercise 1:
10 Drinks (Male) - 200 Pound = .20 - .04 (.01 x 4 hours = .04) =
.16 BAL after 4 Hours and 10 Drinks
Giving coffee to someone who has been drinking will not sober up the drinker. All it will do is wake up the drinker. This could be dangerous because it could possibly cause the drinker to feel that s/he is okay to drive since they are more awake. However, the coffee does nothing to reduce the impairment level of the drinker!
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Exercise 2:
14 Drinks (Female) - 125 Pound Female = .59 - .02 (.01 x 2 hours = .02) =
.57 BAL after 2 Hours and 14 Drinks
She is probably dead. By the way, just like the coffee, a cold shower will simply wake up the drinker not sober her/him up. It could also cause the drinker to suffer a heart attack.
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Exercise 3:
6 Drinks (Male) - 180 Pound Male = .15 - .04 (.01 x 4 hours = .04) =
.11 BAL after 4 Hours and 6 Drinks
6 Drinks (Male) - 200 Pound Male = .13 - .04 (.01 x 4 hours = .04) =
.09 BAL after 4 Hours and 6 Drinks
In order to correctly answer the question regarding the DUI ticket, you must know your own state’s current regulations.
- What is the minimum BAL at a given age that will result in a DUI ticket in your state?
- What are the consequences for someone underage caught drinking and driving at any BAL?
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Exercise 4:
.18 - .08 (.01 x 8 hours) = .10 BAL after 8 Hours
If you drove to the campus, you could have gotten a DUI ticket from the police. Sleep simply provides rest for the drinker. It does not “sober up” a person. By the way, drinking to a level of impairment actually disrupts normal sleep patterns.
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