Comparative antibacterial effectiveness of seven hand antiseptics

Seven hand antiseptics (alcohol-, iodophor- and chlorhexidine preparations) were compared for antibacterial effectiveness using finger-print contact sampling on blood agar in duplicate series with 18 students as test persons. Bacterial samples were obtained before and after handwashing (with unmedicated liquid soap) as well as after hand disinfection. Hibiscrub was tested without prewashing. The antiseptics were rubbed into the skin and the hands left uncontaminated for 2 min before sampling. Due to results showing unexpectedly low antibacterial effectiveness of 70% (v/v) ethanol, a series of supplementary experiments with ethanol (70% (v/v) and 80% (v/v] and isopropanol (60% (v/v] were performed with 10 laboratory staff-members. These experiments confirmed the previously demonstrated weak antibacterial effect of 70% (v/v) ethanol on the normal hand flora. Alcoholic chlorhexidine solutions and Hibiscrub were the only preparations that gave significant, mean reductions (97.9-99.9% and 80.3-93.4%, respectively) in the number of colony forming units. According to the present study, these are the only test preparations that can be recommended for presurgical hand disinfection, and when hand disinfection is needed in general dental practice.