Combating cross-infection

摘要

An intriguing report published in Chemistry World for July refers to a paper presented at the 105th general meeting of the American Society for Microbiology in Atlanta.A group of high school pupils found that the addition of cetrimide to paints and varnishes enabled them to render surfaces that were touched by hand sterile for long periods.The team also tested a series of different metal dusts and salts incorporated into an alkyl based clear and durable varnish.These also proved effective.Colloidal silver was the best of the metals but would be too costly for general use.Varnishes with 25 per cent of copper chlorides self-sterilised within seconds,but the copper added undesirable colour.A varnish containing 2 per cent of quaternary ammonium salts also self-sterilised in seconds but without discolouring the varnish.Aluminium,iron,nickel,tin and zinc compounds took longer to kill bacteria.