Retrospective calculation of blood alcohol concentrations after 'normal drinking'

Within 1 hr 3 groups of 12 persons each were constantly given 0.8, 0.5 and 0.3 g alcohol per kilogram weight in an alcoholic mixture (31%). Under these conditions of a normal process of drinking (BGH 1973) certain waiting times for a retrospective calculation of a higher blood alcohol level than determined must be taken into account as follows: 0.8 g/kg/h - about 2 hr; 0.5 g/kg/hr - about 60 to 90 min; 0.3 g/kg/h - about 30 to 60 min. On the other hand, attention is drawn to the fact that in these times, after the consumption of alcohol, decreases in the blood alcohol concentration to an extent far above the average have to be expected. An extremely careful application of a retrospective calculation of the blood alcohol level is therefore demanded to avoid possible injury in forensic cases.