A composition for the generation of chlorine dioxide including at least one non-iodo interhalide, polyhalide or salt thereof having the formula Br.sub.mCl.sub.nF.sub.oX.sub.p wherein m=0 3, n=0 4, o=0 3, p=0 2, X is a cationic moiety and with the provisos that m+n+o cannot be zero; if m+n+p<2, or mixtures thereof, and at least one source of chlorite ions.