Time to BAC off
The term “Blood Alcohol Concentration” or BAC refers to the amount of alcohol in a person's blood. BAC can be determined by measuring the weight of alcohol in a fixed volume of blood. In Canada, BAC is usually expressed in the number of milligrams of alcohol (weight) in 100 millimeters of blood (volume).
Canadian law specifies that the maximum allowable amount of alcohol in the bloodstream of a driver is 80 milligrams in 100 millimeters of blood - 80mg per cent.
BAC can also be measured in a person's breath by using an instrument called a “Breathalyzer.” Breath tests are just as accurate as blood tests for measuring BAC. This is because blood flows through the lungs, and alcohol molecules pass into air held in the lungs. When a person blows into the breathalyzer, these alcohol molecules are expelled with the air. Because the alcohol concentration in the blood is always about 2100 times greater than the expired air, the breathalyzer can automatically measure the concentration of alcohol in the blood.
BAC is important because it relates to how much you drink; how strongly alcohol affects you; how much grater of a risk you face on the road; and how close you are to breaking the law. The more you drink, the higher your BAC. The higher your BAC, the more physically and mentally impaired you become. The more impaired you are,the higher your risk of a crash. If you drive impaired however, you break the law, no matter what your BAC.
It is no accident that the legal limit is 80mg per cent. At this BAC, one's ability to drive is impaired - many people are very impaired. More importantly, at BACs higher than 80mg per cent, your chances of being involved in a serious road accident are much greater than when you have not consumed alcohol.
Alcohol and the body
Many of us enjoy having a drink. We sometimes consume alcohol as part of a meal, a social occasion or simply to relax. However acceptable, this is, we should keep in mind that alcohol is a drug to be used with understanding and care, and only under suitable circumstances. Knowing alcohols effects is just as important as reading the directions and warnings on a bottle of pills. It's basic preventative medicine to know how your body handles alcohol. This will require some study.
Spirits, wine and beer available in Canada differ in their concentration of alcohol. The illustration shows standard servings for various types of beverages. Each serving contains the same amount of alcohol.
Alcohol Intake
When you have a drink, the alcohol is absorbed directly into your bloodstream through the stomach and and small intestine. The more you drink, the more alcohol will be absorbed, and your BAC will continue to rise. Given enough time - from 30 to 90 minutes or longer - alcohol goes evenly throughout your body.
Alcohol Elimination
Once alcohol has entered your bloodstream, it doesn't simply pass through you. Like most things we eat or drink, the alcohol must be broken down and eliminated. It takes much more time to eliminate alcohol from your body than it does to drink it. Most alcohol is destroyed by a process called oxidation, which breaks down alcohol into carbon dioxide in the liver. The rest is eliminated through the lungs and kidneys. Because the liver's capacity to break down alcohol is limited, it takes time to dispose of the alcohol you have consumed - roughly an hour for a standard serving of alcohol, or about 15mg per cent every hour.
As you drink, alcohol is absorbed in your bloodstream and your blood alcohol concentration rises quickly to a peak. If you stop drinking or consume only one drink per hour, your BAC the levels off and can remain the same for as long as an hour or two because because alcohol is entering your bloodstream at the same rate as it's being eliminated. If you stop drinking at this point, your BAC will then decline steadily at the rate of 15mg per cent every hour. It's important to note that your BAC can rise much more quickly than it falls.
For example, if you have a BAC of 90mg per cent it will take you about six hours to return to a BAC of zero milligrams per cent.
You can't do anything to speed up the elimination of alcohol. Because only a small amount of alcohol is eliminated through tears, saliva and perspiration, you can't dance, jog, sing or cry away alcohol. Frequent urination doesn't help. Drinking black coffee or taking a shower will have no effect on your BAC. Nor is the rate of elimination affected by your weight or tolerance to alcohol. Remember, the experienced drinker takes just as long to eliminate alcohol as the inexperienced drinker. Only time can lower your BAC.
A number of factors influence how fast alcohol is absorbed into your bloodstream. The slower the rate of absorption, the lower the BAC peak will be. So, if you have food in your stomach, your BAC peak will be lower.
Peak BAC also varies with body weight, because blood volumes differ according to body weight. Given the same amount of alcohol, the greater one's blood volume, the lower one's concentration of blood alcohol. Blood volume varies according to two basic factors: recommended ideal body weight based on height and sex, and the type of body tissue that makes up that weight. Larger persons generally have a greater volume of blood which can be distributed. Hence, after drinking the same amount of alcohol, a person weighing 68kg. (150lb.) will have a higher BAC than a person weighing 79kg. (175 lb.) blood volume will be. A 68kg. person who has a lot of body fat will have a higher BAC than a lean 68kg. person of the same sex after drinking the same amount of alcohol.
Women tend to have a higher proportion of fatty tissue than men. Equal amounts of alcohol will, therefore result in a higher BAC for a 60 kg. woman than a 60 kg. man. This means that it normally takes less alcohol for a woman to reach the legal BAC limit than a man.
When we drink, we begin to lose our ability to recognize signs of intoxication. Most people can't judge how impaired they are after drinking. And most people can't accurately estimate their own BAC without the aid of a breath-testing instrument. Therefore, when you have any doubt about your impairment or your BAC, it's best not to drive.
People often ask “How much can I drink and still be safe to drive?” Unfortunately, there is no hard fast rule to follow. Remember, there is no safe limit.
Canadian law specifies that the maximum allowable amount of alcohol in the bloodstream of a driver is 80 milligrams in 100 millimeters of blood - 80mg per cent.
BAC can also be measured in a person's breath by using an instrument called a “Breathalyzer.” Breath tests are just as accurate as blood tests for measuring BAC. This is because blood flows through the lungs, and alcohol molecules pass into air held in the lungs. When a person blows into the breathalyzer, these alcohol molecules are expelled with the air. Because the alcohol concentration in the blood is always about 2100 times greater than the expired air, the breathalyzer can automatically measure the concentration of alcohol in the blood.
BAC is important because it relates to how much you drink; how strongly alcohol affects you; how much grater of a risk you face on the road; and how close you are to breaking the law. The more you drink, the higher your BAC. The higher your BAC, the more physically and mentally impaired you become. The more impaired you are,the higher your risk of a crash. If you drive impaired however, you break the law, no matter what your BAC.
It is no accident that the legal limit is 80mg per cent. At this BAC, one's ability to drive is impaired - many people are very impaired. More importantly, at BACs higher than 80mg per cent, your chances of being involved in a serious road accident are much greater than when you have not consumed alcohol.
Alcohol and the body
Many of us enjoy having a drink. We sometimes consume alcohol as part of a meal, a social occasion or simply to relax. However acceptable, this is, we should keep in mind that alcohol is a drug to be used with understanding and care, and only under suitable circumstances. Knowing alcohols effects is just as important as reading the directions and warnings on a bottle of pills. It's basic preventative medicine to know how your body handles alcohol. This will require some study.
Spirits, wine and beer available in Canada differ in their concentration of alcohol. The illustration shows standard servings for various types of beverages. Each serving contains the same amount of alcohol.
Alcohol Intake
When you have a drink, the alcohol is absorbed directly into your bloodstream through the stomach and and small intestine. The more you drink, the more alcohol will be absorbed, and your BAC will continue to rise. Given enough time - from 30 to 90 minutes or longer - alcohol goes evenly throughout your body.
Alcohol Elimination
Once alcohol has entered your bloodstream, it doesn't simply pass through you. Like most things we eat or drink, the alcohol must be broken down and eliminated. It takes much more time to eliminate alcohol from your body than it does to drink it. Most alcohol is destroyed by a process called oxidation, which breaks down alcohol into carbon dioxide in the liver. The rest is eliminated through the lungs and kidneys. Because the liver's capacity to break down alcohol is limited, it takes time to dispose of the alcohol you have consumed - roughly an hour for a standard serving of alcohol, or about 15mg per cent every hour.
As you drink, alcohol is absorbed in your bloodstream and your blood alcohol concentration rises quickly to a peak. If you stop drinking or consume only one drink per hour, your BAC the levels off and can remain the same for as long as an hour or two because because alcohol is entering your bloodstream at the same rate as it's being eliminated. If you stop drinking at this point, your BAC will then decline steadily at the rate of 15mg per cent every hour. It's important to note that your BAC can rise much more quickly than it falls.
For example, if you have a BAC of 90mg per cent it will take you about six hours to return to a BAC of zero milligrams per cent.
You can't do anything to speed up the elimination of alcohol. Because only a small amount of alcohol is eliminated through tears, saliva and perspiration, you can't dance, jog, sing or cry away alcohol. Frequent urination doesn't help. Drinking black coffee or taking a shower will have no effect on your BAC. Nor is the rate of elimination affected by your weight or tolerance to alcohol. Remember, the experienced drinker takes just as long to eliminate alcohol as the inexperienced drinker. Only time can lower your BAC.
A number of factors influence how fast alcohol is absorbed into your bloodstream. The slower the rate of absorption, the lower the BAC peak will be. So, if you have food in your stomach, your BAC peak will be lower.
Peak BAC also varies with body weight, because blood volumes differ according to body weight. Given the same amount of alcohol, the greater one's blood volume, the lower one's concentration of blood alcohol. Blood volume varies according to two basic factors: recommended ideal body weight based on height and sex, and the type of body tissue that makes up that weight. Larger persons generally have a greater volume of blood which can be distributed. Hence, after drinking the same amount of alcohol, a person weighing 68kg. (150lb.) will have a higher BAC than a person weighing 79kg. (175 lb.) blood volume will be. A 68kg. person who has a lot of body fat will have a higher BAC than a lean 68kg. person of the same sex after drinking the same amount of alcohol.
Women tend to have a higher proportion of fatty tissue than men. Equal amounts of alcohol will, therefore result in a higher BAC for a 60 kg. woman than a 60 kg. man. This means that it normally takes less alcohol for a woman to reach the legal BAC limit than a man.
When we drink, we begin to lose our ability to recognize signs of intoxication. Most people can't judge how impaired they are after drinking. And most people can't accurately estimate their own BAC without the aid of a breath-testing instrument. Therefore, when you have any doubt about your impairment or your BAC, it's best not to drive.
People often ask “How much can I drink and still be safe to drive?” Unfortunately, there is no hard fast rule to follow. Remember, there is no safe limit.
