Kenneth M.Poole Jr.

What Determines Blood Alcohol Content (BAC)?

The percentage of alcohol in the blood depends essentially on three things:

Body Weight: A heavier person has more body fluids, therefore can consume more alcohol than a lighter person, and still have the same percentage of alcohol in the blood.

Amount of Alcohol Consumed: “Standard” drinks all contain the same amount of alcohol. A standard drink is a 12-ounce can or bottle of beer, a 5-ounce glass of most wines, and 1½ ounces (one shot) of liquor.

Most beers have 5% alcohol, most wines have 12%, and 80-proof liquor has 40% alcohol. Multiply the volume of the drink by the percentage of alcohol in each, and the result is the amount of alcohol the body is taking in. In these standard drinks, each contains .60 ounces of alcohol. Each standard drink can correlate to .02 of BAC.

Drinking Time: The more drinks consumed in a shorter period of time, the higher the BAC. Three drinks in one hour will cause a higher BAC than one drink each hour for three hours.

Eating before or while drinking tends to slow the absorption rate of the alcohol into the bloodstream, but eventually all of the alcohol consumed gets into the blood.

Women absorb alcohol into the bloodstream faster and metabolize it slower than men.

Eliminating Blood Alcohol Content

It takes 20 to 40 minutes after a drink has been consumed for all of the alcohol to be absorbed into the body. Because of this, when an individual stops drinking, the BAC will continue to rise for a period of time. An average person’s body will eliminate alcohol at the rate of .015% BAC per hour. This is done through breathing, sweating and through the liver. However, the liver must handle 90% of the alcohol elimination, and the liver never changes speed, so the rate of elimination remains constant. As a result of this slow elimination process, a person can remain impaired for an extended period of time.

How Alcohol Impacts the Body

Absorption: Once alcohol is swallowed, it is not digested like food. Instead, a small amount is absorbed directly by the mucosal lining of the mouth. Once in the stomach, alcohol is absorbed directly into your blood stream through the tissue lining the stomach and small intestine. Food, water and fruit juice help to slow this absorption, while carbonation works to speed absorption.

When the BAC level has reached its highest point and starts to decline, people perceive themselves as being more sober than they really are. They use their highest BAC level as their reference point; unfortunately, this is not when they are sober.

Transportation: Once alcohol is in the blood stream, it is carried to all the organs of the body. In the majority of healthy people, blood circulates through the body in 90 seconds, thereby allowing alcohol to affect the brain and all other organs in 90 seconds.

The effects of alcohol on the body will vary according to the individual; their sex, their body make-up, the amount and type of alcohol consumed, the situation, and the presence of food in the stomach.

Detoxification/elimination: Alcohol is a drug that must be changed into a non-harmful substance.

Ten percent of the alcohol is eliminated through sweat, breath and urine.

The liver must detoxify the remaining alcohol. The liver detoxifies, or breaks down, alcohol at a rate of one half an ounce per hour. However, some people cannot detoxify that much alcohol in an hour. Nothing will speed this rate.

When the rate of alcohol consumed exceeds the liver’s detoxification rate, the amount of alcohol in the bloodstream continues to increase, further impairing the brain, causing intoxication, coma or possibly death.

In summary, it is best to avoid alcohol altogether when planning to drive an automobile or operate a boat. Plan ahead to always have a designated driver or to utilize a taxi service during outings where alcohol is consumed. If ever involved in an incident that results in a charge of driving under the influence or boating under the influence, contact Criminal Defense Attorney Ken Poole at 941.365.7171 or 800.969.5000.