Dental aspirator kits are equipped with amalgam separators, which eliminate the particulate matter from the effluent. When the aspirator kits are disinfected, the disinfectant solution is in contact with the separated amalgams over night and over the weekend Oxidizing components of the disinfectants dissolve mercury from the separated amalgam The dissolved mercury is released into the environment along with the effluent on the beginning of the following workday. The degree of mercury remobilization depends on the amount and oxidizing power of the disinfectant components. The mercury concentrations measured in the effluent of the aspirator kits after the application of seven different disinfectants were 18.4 μg/l – 1396 μ/l. The emission of mercury by dental aspirator kits is lowered substantially by using disinfectants which contain no oxidizing substances. Disinfecting of dental aspirator kits for hygienic reasons is not necessary. Therefore we propose only cleaning rather than disinfecting dental aspirator kits.