The Anatomy of a DUI – How the Body Eliminates Alcohol

In my last blog article (September 02, 2015) I provided a brief overview of how alcohol is distributed throughout the body.  This article will focus on how the consumed alcohol is eliminated from the body.

Elimination: As soon as the alcohol enters the blood stream, the body starts eliminating it by a process in the liver called enzymatic oxidation (metabolism).

39603089_mIn this process, alcohol reacts with oxygen in the body and eventually changes into carbon dioxide and water, both of which are directly expelled from the body.  An enzyme known as alcohol dehydrogenase acts to speed up the reaction of alcohol with oxygen.  The speed of the reaction varies from person to person, and even from time to time for any given person.  On the average, a person’s Blood Alcohol Concentration (BAC) — after reaching peak value — will drop by about 0.015% per hour. For example, if the person reaches a maximum BAC of 0.15%, it will take about ten hours for the person to eliminate all of the alcohol from their body.

For the average-sized male, a BAC of 0.015% is equivalent to about two-thirds of the alcohol content of a standard drink (i.e., about two-thirds of a can of beer, or glass of wine or shot of whiskey). For the average-sized female, that same BAC would be reached on just one-half of a standard drink. So the typical male will eliminate about two-thirds of a drink per hour, while the typical female will burn up about one-half of a drink in that hour.

For example, let’s consider Jack, a 170 lb. male, who met friends for dinner at 8:00 p.m. and had a usual dinner with two glasses of cabernet wine (13.5% alcohol).   Afterwards Jack left the restaurant about 9:45 and decided to stop by the local club.   Jack arrived at the club at 10:00 p.m. and while there drank the equivalent of eight Absolute vodka (40% alcohol) drinks.   I use the term “equivalent” because the “standard” drink contains 1 shot of alcohol (about 1.5 oz.), but we all know that many bars pour stronger drinks.  So even though a person could drink four actual drinks, he could have drank the equivalent of eight “standard” drinks because the actual drinks may contain twice the vodka of a “standard” drink.  Jack finished his last drink at 1:30 a.m.

Under these facts, Jack would reach his peak BAC of 0.162% at 3:00 a.m.   Even though Jack stopped drinking at 1:30 a.m., his BAC will continue to rise until all the alcohol in his stomach is absorbed.   In fact, at 1:30 a.m., the time Jack stopped drinking, his BAC would be about 0.128% and it will continue to rise until it peaks.  Once his BAC peaks, the alcohol in his body will continue to metabolize until he returns to 0.00 BAC (all the alcohol he drank has now burned off or metabolized).

Considering the 0.015% elimination rate per hour (an average), Jack would not return to 0.00 BAC until about 2:00 p.m. the next day!  In fact, if Jack had to drive to work the next morning, he would still have a BAC of 0.103% at 7:00 a.m.   From 11:30 p.m. the night before to about 8:40 a.m. the next morning, Jack’s BAC would be above 0.08%.

Why is this important to understand?  We can control the rate at which alcohol enters our bloodstream; we can gulp down our drinks, or slowly sip them. We can drink on an empty stomach, or we can eat before drinking. We can choose to drink a lot, or a little.  But once the alcohol gets into the blood, there is nothing we can do to affect how quickly it is eliminated. Coffee won’t accelerate the rate at which our livers burn alcohol. Neither will exercise, or deep breathing, or a cold shower. We simply have to wait for the process of metabolism to move along at its own speed.  By understanding how our bodies absorb and eliminate alcohol, we can better control our drinking behavior to avoid a DUI arrest.

In the next part of this article, I will discuss the differences between men and women as they drink alcohol.  Stay tuned… and until then, be safe.

Attorney Manuel J. Barba can be reached at 760-770-3377 or 951-680-9125.  For more information visit