liquid with the surface of element 40 biocide element 40 comprises one or more chemical compounds or element having a biocide and disinfectant effect against bacteria fungi viruses or harmful micro organisms in general thereby preventing the formation and growth of colonies of micro organisms in any part of the washing appliance reached by wash liquid that has been in contact with the biocide element for example biocide element 40 can comprise a concentrate of zinc and or silver in metal or ionic form supported on a suitable support such as glass silica alumina or a polymeric carrier including any synthetic resin which is stable at the temperature of the washing operation colloidal silver is a powerful disinfectant and germicidal agent capable to disable the enzyme that many bacteria fungi and viruses use for their metabolism biocide element 40 can be formulated as a slow release biocide composition so that the antimicrobial and anti fungi action is extended over the time biocide element 40 can be designed as a removable piece in this case the location of the same in the filter chamber u2014 a chamber accessible to users of the washing appliance for cleaning and or replacing the filter u2014 allows replacing the biocide element if necessary also the location of the biocide element in the filter chamber of the washing appliance u2014 a place where wash liquid is forced to flow during operation of the washing pump u2014 is such that the disinfectant action is exerted effectively on the wash liquid itself the dishwasher is advantageously provided with a special function alerting the user when the biocide element is no longer active so that he she is informed for instance by a dedicated part or display of the user interface that it is time to replace.