Alcohol Absorption and the PAS test

A good DUI attorney must understand how the physiology of alcohol absorption effects the facts of the case. Commonly, a preliminary breathalyzer is given by an arresting officer (PAS test). This initial breathalyzer reading is often done close in time to the final consumption of alcohol, which means it may likely be reflective of the "breath" alcohol concentration in the absorptive phase. 

This is important because during absorption, the arteries receive the alcohol first, then the veins. The lungs receive the arterial blood from the arteries, during absorption. Thus, the venous blood alcohol concentration is lower because the veins receive the alcohol after the arteries and lungs. 

They reach an equilibrium after the conclusion of the absorptive phase, when the BAC level reaches it's peak. If there is a PAS result that is close to the legal limit, it may be exculpatory evidence proving that the actual venous blood alcohol concentration, at the same time, had to be lower than the PAS result.  

The Law Office of Ben Mironer has been successful in various cases by utilizing the scientific concepts with the facts of the case. We don't just get reductions and dismissals, we truly earn them.

Alcohol Absorption (Ethanol Metabolism)

When alcohol is consumed, the first step that occurs is scientifically known as the "absorptive phase." The body can't absorb all of the alcohol that is consumed at once, it takes time to enter your blood stream. During that period of time, the "breath" alcohol concentration in a breathalyzer reading will be HIGHER than the "blood" alcohol concentration from a blood draw. 

A good DUI attorney knows how to utilize the scientific facts at hand in any DUI case because these scientific issues never change. But, an attorney must understand how to explain and demonstrate how these scientific issues effect the facts in each individual case. That is where The Law Officeof Ben Mironer can truly help impact the outcome of a case. Our experience and expertise in the field of DUI allows us to get the case results we are able to provide for our clients. See what our clients say.

The Science of Blood Alcohol Content in DUI Defense

How does a breath alcohol concentration reading from a breathalyzer reflect the concentration of alcohol in your blood?

The scientific theory that prosecutors rely on to show that a breathalyzer reading is a reliable way of testing blood alcohol concentration, is a concept known as "Henry's Law." 

Henry's Law essentially explains that a numerical relationship exists between the amount of alcohol in your blood and the amount in your lungs. At a fixed temperature, the numerical relationship between the alcohol in the gas (breath) can be related to the alcohol in the liquid (blood).

The ratio that's commonly used in breathalyzers is 2100 to 1. This means that 2100 milliliters of breath will contain the same amount of alcohol as 1 milliliter of blood. 

Most importantly, the concept of Henry's Law has two fundamental flaws when it is applied to breathalyzer testing for blood alcohol concentration.

The first flaw is the assumption that breath and body temperature are fixed or constant. When air is exhaled, the alveolar air travels through the upper respiratory tract. A drop in temperature occurs before the air is exhaled, which physiologically prevents the breath temperature from remaining fixed or constant. 

The other big flaw is that every person has a different ratio of blood to breath in their body, yet the breathalyzer device converts the reading by using the 2100 to 1 ratio in order to calculate a subject's blood alcohol concentration. If the subject's breath to blood ratio is different from 2100 to 1, then the reading is inaccurate. 

For more information on the relationship between blood alcohol and DUI, please visit www.Mironerlaw.com.