The invention relates to the use of an agent that contains 5 to 99.9% by weight of carbamide and/or at least a derivative thereof, as a cleaning agent e.g. for closed systems, in particular as a dishwasher detergent, as a laundry detergent for washing machines, as an agent for cleaning, sanitizing and/or disinfecting for equipment in the food processing industry and for medical equipment, the use as a hand dishwashing detergent or sanitary cleaner or as a hand cleaner.