Houston DWI Lawyer

Alcohol Absorption and Elimination

Absorption and elimination of alcohol can be a subject of great interest in DWI cases. Blood alcohol content (BAC) of .08% or higher is considered evidence of intoxication and cause for arrest for DWI. BAC is typically determined by a blood or breath test administered by the police. However, the test only shows BAC at the time of testing, not at the time of driving. There is often a significant delay between the time of driving and the time of testing. You may want an experienced Houston DWI attorney to thoroughly examine the factors affecting alcohol absorption and elimination in your DWI case to challenge the validity of your BAC reading as evidence against you.

Attorney Martinez was named as a Clients’ Choice DUI Lawyer on Avvo for 2012. He was named a Top DWI Lawyer by H Texas Magazine for 2011. He has a 10.0 Superb Avvo Rating and more than 15 years’ experience in criminal law. He believes that results do count, and he has successfully defended many clients against DWI charges. You can trust his skill and dedication to defend your rights.

Why is alcohol absorption & elimination important to consider?

It is illegal to drive with a BAC that exceeds the legal limit, but chemical tests are only relevant when looking back in time to determine the driver’s alcohol level at the time of driving. Typically, there is a great lapse of time between the time of driving and the time of testing.

It is difficult to prove the driver’s BAC when driving because of the following variables:

  • Metabolic rate
  • Stomach contents
  • Drinking patterns
  • Passage of time
  • Type of alcohol consumed

Alcohol Absorption and Elimination in the Human Body

Because there are so many variables in the human body when it comes to taking a test, such as those listed above, it is difficult to pinpoint BAC at an earlier time. As time goes on, this difficulty only increases, making it more speculative. This also means that it becomes more valuable to an experienced DWI lawyer who is looking to highlight reasonable doubt in any element of your case.

Alcohol absorption takes time.

When someone consumes alcohol, it goes into the stomach, then the small intestine. This is where a majority of the absorption takes place. The contents of the stomach as well as the type of alcohol consumed impact the speed of absorption.

Elimination of alcohol is immediate.

While the body cannot eliminate alcohol as quickly as it is absorbed, the process begins immediately. This is what initially causes elevated BAC levels. Think of it as a bathtub with a slow drain but no stopper. Water flows into the tub and begins to drain, but the flow of the water is faster than the drain. This means the level increases. Alcohol absorption in the body is quite similar.

Absorption continues after you stop drinking.

This means that your BAC level will increase before it peaks or plateaus. At the peak/plateau, you find absorption and elimination happening at roughly the same rate. You BAC begins to flatten out and stays consistent for a short period. This is typically about 15-45 minutes but depends on your metabolic rate and the contents on your stomach.

Beyond the peak/plateau, the person enters the pure elimination phase. At this point, assuming no additional alcohol consumption, the BAC level steadily decreases. The average rate is about .02 percent per hour. However, this varies from person to person and situation to situation.

If you put this into a graph, it would look like a bell curve – steadily rising to a peak and slowly falling. Even in cases where the test shows BAC above the legal limit, your DWI attorney should know the importance of where on the curve you were at the time of driving. A common issue with breath testing cases is the overestimation of the true BAC when the test is performed during the absorption phase. Breath testing during this phase often overestimates true alcohol levels by anywhere from 40% to 100%.

There are so many factors that can affect a driver’s alcohol absorption and elimination rates. Any good DWI lawyer knows that roadside testing by a police officer is not thorough enough to address all these variables. In the hands of a well-versed defense attorney, this information is extremely valuable. Effective cross-examination on these issues can devastate the prosecution’s DWI case.

Factors Affecting Alcohol Absorption and Elimination

Bodyweight, gender, metabolic rate, food eaten, and tolerance to alcohol are some of the factors that affect alcohol absorption and elimination. The more body mass a person has, the more area in which the alcohol is distributed, the lower the blood alcohol level will be. Women are generally smaller than men, with more body fat and less water content to dilute the alcohol. Higher estrogen levels can also affect the ability to metabolize alcohol. Food eaten during or shortly before the consumption of alcohol can significantly delay its absorption.
Most alcohol elimination occurs in the liver. The less alcohol there is in the blood, the more efficiently the liver can eliminate it. Therefore, any factor that delays absorption will also contribute to elimination. Physically fit people with a higher metabolic rate burn alcohol faster. Tolerance also has a significant effect on the rate of elimination. Generally, people who drink regularly burn alcohol faster than those who do not, and chronic alcoholics burn it even faster.

Are You Ready to Fight DWI Charges?

The experienced DWI defense team at The Martinez Law Firm is dedicated to providing every client with the highest level of legal representation. We regularly fight DWI charges for drivers in Houston and surrounding areas, utilizing our network of resources and well of experience to attain the best outcome in each case. Led by a former prosecutor, we are able to build effective defense strategies based on how the prosecution thinks and functions.

The complex nature of a DWI case is a struggle to navigate alone. Our experienced DWI lawyers will work with you to build a personalized defense strategy and guide you through the path that best suits your particular needs. Entrust our firm with your case today.


Call our Houston DWI lawyer if you have been arrested or charged with DWI in Houston.