What Is the Rising Blood Alcohol Defense in DUI Cases? 

Legally reviewed by:
Rubin, Glickman, Steinberg & Gifford P.C.
July 15, 2021

What Is the Rising Blood Alcohol Defense in DUI Cases? Having a high blood alcohol concentration (BAC) after being arrested for driving under the influence (DUI) is unwelcome news that can lead to sentencing enhancements with harsher penalties in many cases. In Pennsylvania, it’s illegal for drivers with a BAC of 0.08 percent or above to operate a vehicle. However, defense attorneys employ different ways of disputing BAC test results that vary depending on the facts of your case. One way to challenge a Pennsylvania DUI charge is with the rising blood alcohol defense.

What Is the Rising Blood Alcohol Defense?

Rising blood alcohol is a legal defense used to dispute drunk driving charges in Pennsylvania. Your attorney may argue this legal defense because it takes a while for the human body to metabolize alcohol completely. 

After a person drinks alcohol, their BAC gradually rises until it reaches its maximum level. On average, an individual’s BAC peaks 30-45 minutes after they consume alcohol. However, no two people are the same, and various factors can influence the rate at which alcohol is absorbed. While the peak BAC level typically occurs less than one hour after a person stops drinking, in some instances, it may take a few hours. 

This indicates that a driver’s BAC may still rise after being pulled over for a suspected DUI. So, by the time a police officer administers a DUI chemical test, the driver’s BAC may have risen over the legal limit of 0.08 percent

Factors That Influence How Fast Your BAC Rises

Each person’s genetic makeup affects the rate at which their body absorbs and eliminates alcohol. Additionally, various factors also impact how fast your BAC rises, including: 

  • Body fat percentage
  • How fast you consumed an alcoholic drink
  • Interactions with other drugs in your system
  • The type of alcoholic beverage consumed
  • Whether you are sick or tired
  • Whether you have food in your stomach
  • Your gender

For example, if you drink a gin and tonic cocktail on an empty stomach, your BAC will rise faster than if you drank a beer while eating dinner. Also, a person with a higher percentage of body fat absorbs less alcohol from the bloodstream because fat holds less water than muscle. As a result, if two people drink the same number of drinks and eat the same amount of food, the person with a higher percentage of body fat will generally have a higher BAC reading.

How Does Rising Blood Alcohol Cause an Invalid Result on a DUI Test?

Pennsylvania police officers do not always administer DUI chemical tests immediately after pulling over a suspected drunk driver. Instead, a breath or blood test is often conducted to measure BAC at the police station after an arrest takes place. 

DUI test results are usually regarded as valid if administered within two hours after you last drove. For some people, their BAC may still be peaking during this time, while others’ BAC may be falling. However, BAC drops more slowly than it rises. Consequently, even though it may be falling, it may not have fallen back to where it was when you were driving. 

Suppose the arresting officer does not obtain your BAC results within two hours. In that case, the prosecution must prove your BAC using results from a roadside breathalyzer test or demonstrate that you had additional illegal substances in your system outside the two-hour window. Furthermore, the prosecution must provide a good reason why a DUI chemical test could not be performed within the two-hour limit.

How Can Rising Blood Alcohol Be Used as a Defense in a Pennsylvania DUI Case?

When applying the rising blood alcohol defense, a skilled DUI defense attorney and expert witness may be able to “back out” a defendant’s probable BAC results at the time they were driving. Establishing this defense typically requires testimony from an expert witness who’s knowledgeable about the process to explain the science behind how the human body metabolizes alcohol to a judge or jury. 

Although not a defense to all cases, the rising blood alcohol defense may be useful in cases where the BAC is close to one of the statutory limits. Where the alcohol testing method has a margin of error, coupled with the rising BAC defense, there could be significant differences in applicable sentences. Also, this might be sufficient to establish reasonable doubt about whether you were driving impaired with an over-the-limit BAC. In other cases, it may persuade the prosecutor to dismiss DUI charges or accept a plea deal for some kind of a lesser charge.

If you’re facing DUI charges in Pennsylvania, talk to an experienced DUI defense lawyer who can investigate your case in detail and explain the best possible defense strategies to achieve the most favorable results. 

Talk to a Skilled Pennsylvania DUI Defense Lawyer in Montgomery County for Free 

A Pennsylvania DUI conviction can lead to severe consequences, including a loss of license, hefty fines, and possible jail time. A seasoned DUI defense attorney from Rubin, Glickman, Steinberg & Gifford, P.C. are here to evaluate your case and determine the most fitting challenges to dispute your charges and do everything possible to protect you from the implications of a DUI conviction. 

For over 65 years, our lawyers have advocated for the rights and freedoms of individuals facing criminal charges in Montgomery County and across Southeastern Pennsylvania. We are prepared to discuss your situation and provide strategic defense options to achieve the best possible results. To speak with one of our skilled DUI defense lawyers about your situation, schedule a free consultation by completing a contact form or call 215-822-7575.

Legally reviewed by:
Rubin, Glickman, Steinberg & Gifford P.C.
Pennsylvania Attorney's
July 15, 2021
Established in 1952 by Irwin S. Rubin, Rubin, Glickman, Steinberg & Gifford P.C. boasts over 65 years of experience serving clients throughout Pennsylvania. Renowned for its commitment to ethical representation, the firm has garnered prestigious accolades, including being named the "Best Law Firm" for its outstanding legal defense work by U.S. News & World Report. Their team of seasoned attorneys, recognized as Pennsylvania Super Lawyers and Rising Stars, brings unparalleled expertise to a wide range of legal matters, ensuring exceptional representation for individuals, families, businesses, and organizations.