Abstract: A composition, which is suitable for use as an ITC block is disclosed, which has advantageous properties related to in-use life span. The composition comprises: (a) 35 to 65% w/w of an anionic detergent (surfactant) selected from alkyl benzene sulphonic acids, alpha olefine sulfonates, long chain fatty acid sulphates, higher fatty acids, (is well as the alkali metal and alkaline earth metal salts thereof, and natural detersive agents, and mixtures of any of these; (b) 3 to 15% w/w of a non-ionic detergent (surfactant) selected from alkoxylated alkyl phenols and alkoxylated fatty alcohols, (c) 5 to 10% w/w of a water-swellable cellulose derivative or a salt thereof wherein the cellulose derivative exhibits a viscosity of at least about 1500 cps, measured in a 1% aqueous solution at 25° C.