Calcium hypochlorite compositions that are classified as a Packing Group III Division 5.1 oxidizer material or as a non-Division 5.1 oxidizer material are described. In one embodiment, the compositions comprise an admixture of particulate calcium hypochlorite and particulate metaboric acid. The calcium hypochlorite is present in the composition in an amount and is of a concentration such that the composition would be classified as a Packing Group II Division 5.1 oxidizer in the absence of said particulate metaboric acid. Other embodiments described are solid shaped articles, e.g., tablets, comprising the described calcium hypochlorite-metaboric acid composition.