Abstract: The present invention relates to an activator of peroxo compounds, its method of manufacture, and its method of use. The activator is useful as an additive to textile cleansing and disinfecting agents that contain peroxo compounds. The invention permits the bleaching and disinfecting of textiles at temperatures between 25.degree. C. and 60.degree. C.The activator comprises a combination of the following compounds, by weight: (a) phthalic anhydride (4-98%); (b) N-acetylphthalimide (2-96%); (c) phthalimide (0.1-28%); (d) stabilizer (0.2-25%) and/or (e) soluble polymer (0.2-12%); wherein the stabilizer is an aliphatic carboxylic acid having from 12-22 carbon atoms, the polymer is soluble in water or in organic solvents, and the particle size of the final activator composition is from 0.1 to 3.5 mm.