A large group of in-can preservatives are based on the sodium salts of phenol derivatives of the ortho-phenyl phenol, parachloro meta-cresol, penta and tetrachlorophenol types. These are available in granular, flake or solid form, or as highly alkaline solutions. A particularly effective product, tested in the UK and now accepted throughout Europe and USA is based on 1:2. benzisothiazolin-3 one. Bactericidal activity is obtained even against repeated gross contamination, at concentrations within the range 0.01/.05%. Products based on this chemical are in liquid form, therefore, easy to handle and meter.`-They possess low mammalian toxicity. The oral LD is in the range 0.625-1.25 grams per kilogram body weight compared to 0.038g/kg for phenyl mercuric acetate and less than 0.1 g/kg for sodium pentachlorophenate.