Abstract: A process for the decomposition of a halogenated organic compound which comprises contacting the compound with a polyglycol and an alkali or alkaline-earth hydride, optionally in the presence of an alkali salt, at a temperature which does not exceed 100.degree. C., and under an atomosphere having a reduced oxygen content.The process is particularly useful for the decontamination of industrial oils containing chlorinated biphenyls because the treated oil is not degraded during the decontamination process.