According to the definition in the Directive 98/8/EC, transposed into the Decreto Legislativo n. 174 of the 25th of February 2000, the term Biocides refer to “active substances and preparations containing one or more active substance, presented in the form in which they are supplied to the user, intended to destroy, deter, render harmless, prevent the action of, or otherwise exert a controlling effect on any harmful organism by chemical or biological means”. The purpose of this definition is to group together into a single class all the products displaying a “biocidal” action, designed for the control and the removal of harmful organisms. Disinfectants, insect-repellents and other products registered as Presidi Medico Chirurgici (Medical-Surgical Devices), but also microorganisms and viruses performing a biocidal activity, belong to the Biocide classification.