["Alco Screen"--a reliable method for determining blood alcohol concentration by saliva alcohol concentration?]

About two years ago pharmacies in the Federal Republic of Germany began to offer motorists test sticks named "Alco Screen" in order to evaluate the concentration of alcohol in the saliva. According to the producers it should be a quick and simple method giving a high correlation between the alcohol level both in blood and saliva. As advertised, a drunken driver could estimate his own extend of alcohol impairment by himself. We checked the reliability of this method by comparing the alcohol level in the blood with the extend of colour change of the sticks in 20 adult volunteers engaged in drinking tests. 85% of them demonstrated distinct discrepancies. In most cases the saliva concentration estimated was too low. Those, depending on the result of this test kit, take a high risk of being misled and can probably assume sobriety in contrast to their actual state. A warning concerning this test is necessary.