The cleaning brush uses small silver particles inside the plastic as bacteria cannot survive on the material treated with it. Elemental silver is one of the oldest known antiseptics in human history. It is already effective in very small concentrations, in which although it has it’s antibacterial effect, it is harmless to humans because it doesn’t show any cytotoxicity. Due to its versatile effects resistances only occur very seldom. Furthermore it doesn’t have any known allergic potential and isn’t cumulative. Alternatively used agents such as organic or organometallic compounds or inorganic salts all show more or less cytotoxic effects. Size: Length: 9.6 Inches