To assess the working conditions of medical staff the authors compared mercury vapor concentrations released during manipulations with various copper amalgams, TMAC-01 tableted copper amalgam manufactured by Nikitiv Mercury Plant, its foreign copper analog manufactured be "Becht" (Germany), and a new CMTA capsulated copper amalgam. Use of CMTA copper amalgam was found not hazardous for medical staff provided sanitary and hygienic regulations were adhered to. Moreover, mercury vapor concentrations released during work allow its use in rooms without ventilation cabinets, whereas tableted copper amalgams TMAC-01 and Becht may be used only in dentistry rooms equipped with such cabinets.