N,N diacyl O-substituted imide bleach activators and compositions employing them are provided. The activators have the general formula: ##STR1## wherein X is selected from O, NR.sup.16 and S; e is 0 or 1; f is 0 or 1; R.sup.16 is selected from H and C.sub.1 -C.sub.4 linear or branched, saturated or unsaturated alkyl groups; and R.sup.1 is preferably phenyl or C.sub.7 -C.sub.13 linear or branched chain, saturated or unsaturated alkyl; R.sup.2 is preferably C.sub.1 -C.sub.10 branched or unbranched, saturated or unsaturated alkyl and R.sup.3 is preferably C.sub.1 -C.sub.12 linear or branched chain, saturated or unsaturated alkyl. Bleach additive and bleaching compositions including the bleach activators and methods of cleaning fabrics are also provided.