HALL - CARPENTER, CO.
By Edwin T. Scallon, Copyright © 1990, 1995, 2008, 2020 All Rights Reserved
ACCIDENT RECONSTRUCTION AND BAC CALCULATION PROGRAMS
HISTORY OF WIDMARK'S FORMULA
Unless one can read German, Widmark is a tad difficult to understand. Fortunately, his experiments and later his paper(s) which he delivered in Sweden in 1932 were somewhat translated. Again since mathematics is a universal language, it is not that difficult to understand what he postulated. The more interesting thing I learned was what he called his 'r' factor. We use this 'r' factor in calculating the subject's BAC. Initially I thought like most mathematicians or scientists, it was an arbitrary variable. Actually, it stands for the "(r)educed body mass" or (in German, as originally written) "(r)edzierte kopermasse". In other words Widmark postulated that approximately .68 of a person's weight can hold alcohol. The rest of body weight is actually stuff called adipose tissue, like bone, or fat, which can not hold alcohol. This is why men (usually more muscular than women) can hold more alcohol than his female counterpart since the body mass of a female (usually) is less dense and contains more fat than muscle; muscle holds alcohol and fat does not.
Interesting to note that an attorney, Ed Kuwatch, Esq. has published a rather fascinating blog about the Widmark Formula. Historically, however, Ed cites a book, Principles and Applications of Medicolegal Alcohol Determination (Littleton, MA: PSG Publishing Co. (1981), as his reference and that book is also available on line. Essentially it gives the historic look at experiments by Professor E.P.Widmark of Sweden, which lead to his paper on BAC. BAC is Blood Alcohol Concentration and not to be confused with BrAC which stands for Breath Alcohol Concentration.
Widmark's Formula originally dealt with the amount of alcohol consumed