Skip to Content

Blood-Alcohol Physiology

Blood-alcohol analysis is simply the attempt to measure the percentage by weight of alcohol within the DUI suspect’s blood at the time of testing. This is done directly when dealing with a blood sample, or indirectly by analyzing the percentage in a breath or urine sample and applying conversion ratios to estimate the percentage in the blood; these conversion ratios used in DUI cases are inaccurate in that they simply represent statistical averages.

In dealing with a charge of violating Vehicle Code section 23152(b), driving with 0.08% blood-alcohol concentration (BAC) or more, the amount of alcohol in the blood at the time of driving is the only issue. Where, however, the DUI charge is violation of Vehicle Code Section 23152(a) (and it is common to charge both offenses), the amount of alcohol in the blood is of only secondary interest. It is the amount of alcohol actually absorbed into the brain that will affect the individual’s ability to perceive, make judgments, and coordinate movements; the individual’s ability to safely operate a motor vehicle. But in DUI cases there is no practical means of measuring the alcohol absorbed by the body beyond that found in the bloodstream or, even further removed, in the urine or breath. Since the bones, brain, and fatty tissue contain a much lower percentage of water than does blood, and since the alcohol level in blood is about 17 percent higher than that in the soft tissues, the concentration of alcohol in the entire body, including the brain, is always less than that in the blood. However, science has offered the “Widmark Factor R,” a designation of the ratio between the concentration of alcohol in the whole body divided by the concentration of alcohol in the blood. This ratio averages about .67 for men, with a range of .46 to .86; women usually have a somewhat lower ratio because of having a larger proportion of fatty tissue. Obviously, the fact that this ratio varies so widely according to the individual makes generalizations in a given DWI case very suspect.

Continue Reading Read Less
    "This is a top level law firm. The Bible of DUI's comes from this firm!"

    This is a top level law firm. The Bible of DUI's comes from this firm! These are the guys other attorneys call when they are ...

    Tania C.
    "Mrs. Normandeau is by far the hardest-working and most diligent attorney I have ever met."

    I cannot express enough gratitude towards Taylor and Taylor's Attorney, Jeanne Normandeau. I hired Mrs. Normandeau for a VERY ...

    Bruce R.
    "I have come across many attorneys in my life and I have never been treated as well as I have her"

    I have come across many attorneys in my life and I have never been treated as well as I have here. Every phone call was ...

    Anthony D.
    "Christopher always made me aware of what was going on with my hearings, and got me the best outcome possible."

    When you need to get a lawyer, you aren't usually in a great situation. I wasn't at least. Christopher and his team never ...

    Jessica S.
    "Jeanne Normandeau is a great lawyer. She knows how the Riverside court judges work."

    Jeanne Normandeau is a great lawyer. She knows how the Riverside court judges work. She will fight for you and will get you ...

    Joe E.
    "I would recommend this firm with no qualms!"

    I received counsel in a sensitive legal matter from Lawrence Taylor Sr., and his advice was spot on. I did some research and ...

    Jerry S.
    "They will fight strategically to help you win your case."

    These are the best lawyers in LA/OC when it comes to DUI cases. They will fight strategically to help you win your case. My ...

    Kendall L.
    "Thankfully Mr. Taylor was able to help fight my case without me ever having to go to court"

    You should never drink and drive anywhere, but especially don't do it in la Jolla! Cops down here have nothing better to do ...

    Steven K.
    "Chris not only got me down to a Wet Reckless but was able to significantly reduce the penalties I would face."

    Im am so glad that I read the reviews of Taylor and Taylor after my first "incident" and immediately contacted them. Chris ...

    Suzi J.
    "Won DMV hearing and got my case expunged for a minor issue"

    Truly great team of lawyers. Handled everything the very best they could. Won DMV hearing and got my case expunged for a ...

    Nick T.
Orange County's Premier DUI Defense Attorneys

With an average of 32 years of experience, a top A-V rating, and a listing in the Bar Register of Preeminent Lawyers, the firm continues to be widely recognized as California’s premier DUI defense attorney's and has twice been recognized in the American Bar Association Journal for its specialization and unique technical support staff of former law enforcement, blood-alcohol and DMV experts.

Tailored Defense For You

Whether you have questions or you’re ready to get started, our legal team is ready to help. Complete our form below or call us at (562) 330-4173.

  • Please enter your first name.
  • Please enter your last name.
  • Please enter your phone number.
    This isn't a valid phone number.
  • Please enter your email address.
    This isn't a valid email address.
  • Please make a selection.
  • Please enter a message.
  • By submitting, you agree to be contacted about your request & other information using automated technology. Message frequency varies. Msg & data rates may apply. Text STOP to cancel. Acceptable Use Policy