QUAB 151 and the corresponding epoxide compounds of chlorohydrin reagents (QUAB 188, QUAB 342, QUAB 360 and QUAB 426) react with substrates carrying hydroxyl, amino, mercapto, carboxyl and other functional groups. The epoxy function affects the permanent chemical bonding of a quaternary ammonium group to the substrate. The quaternary ammonium group lends cationic character to the adducts and is stable over a wide range of pH.