Abstract: The incorporation of many percarboxylic acids in household formulations is precluded from by adverse physicochemical properties, such as a propensity to decompose too quickly during storage or explode on impact or when subjected to pressure, though otherwise they would be effective disinfectants and bleaching agents, especially at hand-hot temperatures.The invention provides a stable and effective selection of organic percarboxylic acids which satisfy one or other of the general formulae (1) or (2):R.sup.a --CO--NH--C.sub.6 H.sub.4 --CO--OOH (1)orHOO--CO--R.sup.b --CO--NH--C.sub.6 H.sub.4 X (2)in which in formula (1) the amido substituent is meta or para to the percarboxylic acid group and R.sup.a represents an alkyl group containing from 1 to 5 carbons in formula (1) and in formula (2) R.sup.b represents a branched or preferably linear alkylene group containing from 4 to 7 carbon atoms of which at least 4 are linear and X represents hydrogen or a substituent like chloride.