[Investigations on the influence of different mouth and nose protection masks on the evidential breath alcohol measurement].

On the occasion of a judicial expert opinion on the question of whether wearing a face mask can lead to a falsification of the breath alcohol value leading to detriment of the accused, an experimental series of tests was carried out under pandemic conditions on six healthy test subjects (four men, two women), who practiced low-risk recreational alcohol consumption. On each day of the study one specific mask type (surgical mask, textile mask, FFP2 mask) was examined. After ingestion of an individually calculated amount of alcohol and a 30-min absorption phase, 6 consecutive breath alcohol measurements were carried out at 30-min intervals, with one mask or no mask worn between measurements. Subsequently, pairs of values for periods with and without a mask were formed and the hourly breath alcohol elimination rates were calculated. As a result, the breath alcohol elimination rates with and without masks did not differ from each other. There were no error messages from the breathalyzer that can be attributed to the previous wearing of a mask.