how does one convert a 0.39 ETOH result on a blood test into BAC(grams of alcohl per 100 mL of blood)? i thought i went to law school so i could avoid this sort of math and science, but here i am.

also, how the heck is ETOH supposed to be an abbreviation for ethanol?

Drew,

As someone who did poorly in High School Math and took no math in college I share your pain. The good news is that a relatively simple math formula will get you where you need to be. I assume this is a hospital drawn sample (that tested Plasma or Serum) that you are trying to translate to whole blood terms. The formula to use (per my expert) is to divide the hospital ETOH number by 1.16 and that will give you a .33 result. A treatise source for that formula is Medical-Legal Aspects of Alcohol 4th Edition (pg 63)

"How the heck is ETOH supposed to be an abbreviation for ethanol?"

Ah, chemistry.

"OH" signifies alcohol. (-OH is what is called a hydroxyl functional group; it's made from an oxygen atom "O" attached to a hydrogen atom "H").

"ET" tells you which kind of alcohol (meaning what is attached to the -OH group), here ethyl alcohol aka ethanol (the type of alcohol that results from natural fermentation, the kind of alcohol people drink). Actually, there is nothing that goes by E or T attached; ethyl refers to a complex called an ethyl radical, made of carbon and hydrogen arranged a certain way.

Further info at:

http://www.chemcases.com/alcohol/index.htm#Alcohol%20and%20Organic%20Substances:

.33!!!!

wow. well, i guess you learn something new everyday. thanks for your help and the for the cites.

We get these calls all the time from prosecutors. Typically, hospital results are in mg/dl. Since the Texas law is in g/dl a conversion is required. IF the sample is whole blood, then all that one needs to do is move the decimal place over three places. For example, if the whole blood sample from the hospital was 33 mg/dl then the conversion to g/dl would be 0.033 g/dl. Hope this helps.

Artie Waller
Regional Lab Manager
Texas DPS Crime Lab - Abilene