Sensitive and/or chemically reactive detergent additives can be shaped in the form of spherical particles having the desirable properties of being non-friable, non-dusty and at the same time fast-dissolving. The process comprises the steps of treating a mixture comprising said detergent additive and a hydratable material with a polymeric material of high Tg in a high-speed mixer/granulator. A preferred detergent additive is a peroxyacid bleach precursor.