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  • Writer's pictureWilliam Matthews

Blood Alcohol Concentration (BAC) and Its Impact on DUI Cases, Orlando DUI Attorney

Updated: Aug 23, 2023

Driving under the influence (DUI) is a serious offense that poses a significant threat to public safety. One of the key factors that law enforcement officers use to determine whether an individual is impaired while operating a vehicle is their Blood Alcohol Concentration (BAC) level. In this article, we'll delve into the science behind BAC, its impact on DUI cases, the legal thresholds, and possible defenses that can arise in such cases. It's important to hire an Orlando DUI attorney as soon as possible.

Understanding Blood Alcohol Concentration (BAC): The Science

BAC is a measure of the amount of alcohol in a person's bloodstream, expressed as a percentage. It is influenced by several factors, including the amount of alcohol consumed, the rate at which alcohol is metabolized by the body, body weight, and overall health. When alcohol is consumed, it is absorbed into the bloodstream through the stomach and small intestine. It then travels to the liver, where it is broken down and eliminated. The BAC is affected by the balance between alcohol consumption and elimination.

The Impact of BAC on DUI Cases

Different jurisdictions have established legal BAC limits for drivers. These limits are set based on scientific research and are intended to provide a clear threshold beyond which an individual is presumed to be impaired while driving. In the United States, for example, the legal BAC limit is typically 0.08%, although it can vary by state. Exceeding this limit can result in serious consequences, including fines, license suspension, and even jail time.

Law enforcement officers use various methods to measure BAC, including breathalyzer tests and blood tests. These tests provide an accurate assessment of an individual's impairment level at the time of testing. However, it's important to note that impairment can still occur at BAC levels below the legal limit, and some drivers might experience impaired judgment, slower reaction times, and decreased coordination even before reaching the legal limit.

Possible Defenses in DUI Cases

While BAC testing is a reliable method for assessing impairment due to alcohol consumption, there are instances where defenses can be raised in DUI cases. Some possible defenses include:

  1. Accuracy of Testing Equipment: Breathalyzer devices and blood tests must be properly calibrated and maintained. If there are issues with the testing equipment's accuracy or maintenance, the results could be called into question.

  2. Rising BAC Defense: Alcohol takes time to be absorbed into the bloodstream. It's possible for a person's BAC to continue rising even after they have stopped drinking. This could lead to a situation where the BAC at the time of testing is higher than it was when the person was actually driving.

  3. Medical Conditions: Certain medical conditions and medications can affect BAC readings. Individuals with conditions that cause fermentation in the digestive system might produce alcohol internally, leading to falsely elevated BAC results.

  4. Procedural Errors: Law enforcement officers must follow proper protocols when administering BAC tests. Failure to do so could result in the results being deemed inadmissible in court.

  5. Challenging Probable Cause: If the initial traffic stop lacked probable cause, any evidence collected afterward, including BAC results, might be suppressed in court.


Blood Alcohol Concentration (BAC) is a crucial metric in DUI cases, providing insight into a driver's level of impairment. Legal BAC limits exist to ensure the safety of all road users. However, understanding the science behind BAC, legal thresholds, and possible defenses is essential for both law enforcement officials and individuals facing DUI charges. Responsible alcohol consumption and prioritizing safety on the road are paramount to preventing DUI cases and their potential consequences. Hire an Orlando DUI attorney as soon as possible. If you have been charged with any criminal offense, give Matthews Criminal Defense a call today at my Orlando, Florida office at (407) 561-8166 for a free consultation.

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