Stabilization of chlorinated phenols

Pentachlorophenol containing in admixture therewith a stabilizing amount of at least one member of the group consisting of C.sub.4 to C.sub.30 unsaturated fatty acids, esters of said fatty acids, and epoxides.

A process for inhibiting the formation of chlorinated dibenzo-p-dioxin in molten pentachlorophenol which comprises adding to the pentachlorophenol about 0.01 to about 1 percent, based on the weight of the weight of pentachlorophenol, of at least one stabilizer selected from the group consisting of C.sub.4 to C.sub.30 unsaturated fatty acids, esters of said fatty acids, and epoxides having a boiling point of at least 150.degree. C.

In a process wherein pentachlorophenol is maintained at a temperature above its melting point, the improvement which comprises admixing with the pentachlorophenol 0.01 to 1.0 percent, based on the weight of pentachlorophenol, of at least one stabilizer selected from the group consisting of C.sub.4 to C.sub.30 unsaturated fatty acids, esters of said fatty acids, and epoxides having an atmospheric boiling point of at least 190.degree. C.

In a process wherein pentachlorophenol is purified by distillation, the improvement which comprises adding to the pentachlorophenol to be distilled about 0.01 to 1.0 percent, based on the weight of pentachlorophenol, of a stabilizer selected from the group consisting of C.sub.4 to C.sub.30 unsaturated fatty acids, esters of such fatty acids, and epoxides.