Abstract: There is disclosed a method for the preparation of an oxidant-containing solid which is useful as an antiseptic agent, bleaching agent, oxidizing agent, etc. The solid, which can be prepared in a varied degree of water solubility, is prepared by reacting, in aqueous solution an alkali metal silicate with an oxidant which can be hydrogen peroxide or an alkali metal hypohalite. When a hypohalite is used as the oxidant, the resultant solid can be prepared in a varied degree of water solubility. Typically, a solution of sodium silicate is admixed with a solution of sodium hypochlorite, resulting in the formation of a voluminous, white precipitate that can be separated by filtration, decanting and the like, to obtain a solid containing the hypochlorite. The water solubility of this solid can be readily controlled by progressive dehydration of the solid, resulting in increasing water insolubility of the solid.