Mixtures of halocarbons which contain fluorine and chlorine and/or bromine (e.g. a mixture of CCl.sub.2 FCF.sub.3 with CClF.sub.2 CF.sub.3, CCl.sub.2 F.sub.2, CClF.sub.2 CClF.sub.2 or CHClF.sub.2) are contacted with hydrogen in the presence of silicon carbide and/or a metal selected from aluminum, molybdenum, titanium, nickel, iron or cobalt (or their alloys) at temperatures of 350.degree. to 700.degree. C. and pressures of 0 to 1000 psig to obtain a product mixture which substantially corresponds in terms of the distribution of fluorine substituents on carbon atoms with the mixture of halocarbon starting materials.