The measure of alcohol intoxication for legal and medical purposes is referred to as blood alcohol content (BAC), or blood alcohol level. Blood alcohol content is greatly affected by a number of factors including the type of alcohol being consumed, the amount of alcohol being consumed, and the weight of the person consuming said alcohol. There are charts available that can give you an approximate BAC based on your weight and how many drinks you have consumed. Blood alcohol content is generally expressed as the percentage of alcohol in the blood. BAC is commonly used by law enforcement to catch drunk drivers.
How BAC is Measured
In the US, blood alcohol content is the weight of alcohol (ethanol) in 210l (liters) of breath or 100ml (milliliters) of blood. It is measured in grams. BAC is measured in a few different ways. If someone is pulled over and suspected of driving under the influence, they will likely be given a Breathalyzer test to measure the amount of alcohol in their blood. If a Breathalyzer test is refused, BAC can also be determined with a urine or blood test.
While drunk driving laws will vary by state, many states define legal intoxication as having a blood alcohol content of .08 or higher. Lower BAC levels can and will still affect the skills needed to drive and may still get people into legal trouble. It is important for this reason to refrain from drinking at all when planning to drive. Even one drink could have an affect on your blood alcohol level.
Extremely High BAC Levels
When someone consumes a large amount of alcohol, their BAC can become very high as they will have a large concentration of alcohol in their bodies. If a person’s BAC is in the vicinity of .20, they risk losing consciousness, and face blackouts. Those with a BAC of .30 face loss of consciousness, severe depression of the central nervous system and possibly death. Those with a BAC of .40 face loss of consciousness and possible death, and those with a BAC of .50 or higher face an extremely high possibility of alcohol poisoning and the possibility of death.
Consuming alcohol is not bad as long as it is done responsibly and in moderation. Arranging for transportation if you plan to drink can help you avoid making poor decisions and potentially getting charged with driving under the influence. To learn more about blood alcohol content and alcohol consumption, consult the following resources.
Further Resources on BAC
- Blood/Breath Alcohol Concentration Calculator – A calculator that can help determine approximate BAC; users enter weight, number of drinks consumed, the time period in which drinks are consumed, and gender.
- BAC Charts – BAC charts for both men and women that can help determine an approximate blood alcohol concentration.
- How Breathalyzers Work – An article explaining exactly how Breathalyzer tests work in measuring the amount of alcohol in one’s system.
- Drinking: Men and Women are Unequal – An article discussing how men and women process alcohol differently due to factors such as proportion of fat in the body.
- Blood Alcohol Concentration – An in-depth explanation of blood alcohol content and some of the research that has been done.
- The ABCs of BAC – A PDF guide to understanding blood alcohol content and alcohol impairment from the National Highway Traffic Safety Administration.
- Understanding Alcohol Poisoning – A definition of alcohol poisoning as well as signs and symptoms from the Mayo Clinic.
- Drunk Driving Statistics – A list of statistics regarding drunk driving from MADD.
- State Drunk Driving Laws – Information on state drunk driving laws from the Governors Highway Safety Administration.
- The High Cost of Drinking and Driving – Facts on the consequences of driving under the influence, including information on the financial consequences.
- Social Consequences of Drinking and Driving – (PDF) – An article discussing the social consequences of drunk driving.
- BAC Information – A chart with information on how different BAC levels with affect the body and lead to potential death.
- Blood Alcohol Concentration Limits – Information on the laws addressing BAC limits for drivers operating noncommercial vehicles.
- Binge Drinking – Information from the Centers for Disease Control and Prevention on binge drinking.
By Ted Burgess