Comparison of blood alcohol levels with breath alcohol levels measured using the Drager 7110 MKIII breathalyzer

Abstract

Background Breathalyzers have become an indispensable tool for monitoring alcohol levels among drivers for evidential purposes. Israels traffi c police, like many other countries worldwide, uses the Drager 7110 MKIII, which is correlated with blood alcohol levels at a 2100:1 partition ratio. Recent uncertainty with this association resulted in a legal standstill in the conviction of drunk drivers. Objective To assess the correlation between breath alcohol, measured using the Drager 7110 MKIIIIL breathalyzer, and blood alcohol concentrations (BAC). Methods Sixtyone healthy volunteers, ages 21–37 years, participated in a blinded study. Participants were administered between 0.89 and1.16 g 95% alcohol/kg body weight according Injury Prevention 2010;16(Suppl 1):A1–A289 A148 to gender mixed with juice. Breath and blood samples were taken simultaneously before and at 30, 60and 90min after alcohol ingestion. Breath alcohol concentrations were measured by police offi cers trained in the use of the breathalyzer and under fi eld conditions. Blood alcohol levels were determined by headspace gas chromatography technique in an accredited laboratory. Results A total of 242 valid blood/breath tests were performed on 61 participants. The correlation coeffi cient between breath and blood alcohol levels was high (r=0.983). The regression equation for the prediction of breath alcohol was equal to 10.224+4.292*blood alcohol. The sensitivity and the specifi city of the breathalyzer instrument were 97% and 93%, respectively. Blood to breath alcohol ratio was 1:2231242. Conclusions The Drager 7110 MKIII IL breathalyzer was highly correlated with BAC. The results of this study were used in the Israeli courts as evidence for the reliability of the Drager 7110 MKIII breathalyzer measurement.