Evaluation of the bactericidal activity of a disinfectant containing sodium hypochlorite (Amiclor)

We evaluated the stability and the bactericidal activity of a disinfectant containing sodium hypochlorite (Amiclor), which associates the buffer effect of the system sodium carbonate/sodium tetraborate to the stabilizing action of sodium chloride. The stability was determined evaluating the trend of the active chlorine title in various conservation conditions and comparing it with a product having only sodium chloride as stabilizing component. The bactericidal activity, instead, was evaluated by suspension and surface tests against Escherichia coli (ATCC 10536) and in relation to several variables, as product concentration, contact time, presence of interfering substances and water hardness. From the obtained data it is possible to affirm that Amiclor owns a greater stability as regards the traditional products stabilized only with sodium chloride. The activity tests have pointed out that the practical conditions affect the choice of the combination "product concentration/contact time" necessary to obtain an effective bactericidal activity. The activity of Amiclor is conditioned by the presence of proteins in the mixture or on the surface of reaction. This influence is not very clear in clean conditions while it considerably increases in dirty conditions. A decrease of bactericidal activity was observed when the product was diluted in hard water, mainly for contact times of 5 minutes or low product concentrations.