tolutriazole 2 methyl benzimidazole 3 5 dimethyl pyrazole and methylene bis benzotriazole an effective amount of the foregoing additives for use in a refrigerant compression is generally in the range from 0 1 to 5 0 by weight for the antioxidants 0 1 to 5 0 by weight for the corrosion inhibitors and 0 001 to 0 5 percent by weight for the metal deactivators the foregoing weight percentages are based on the total weight of the polyether polyols and the esters it is to be understood that more or less of the additives may be used depending upon the circumstance for which the final composition is to be used examples of refrigerants useful in this invention are hydrochlorofluorocarbons such as chlorodifluoromethane chlorofluoromethane 2 2 dichloro 1 1 1 trifluoroethane 1 chloro 1 2 2 2 tetrafluoroethane 2 chloro 1 1 2 2 tetrafluoroethane 1 chloro 2 2 2 trifluoroethane 1 1 dichloro 1 fluoroethane and 2 chloro 2 2 difluoroethane examples of hydrofluorocarbon refrigerants useful in this invention are 1 1 1 2 tetrafluoroethane 1 1 2 2 tetrafluoroethane 1 1 1 trifluoroethane 2 2 difluoroethane trifluoromethane methylene fluoride methyl fluoride difluoroethylene and pentafluoroethane several examples of the present invention with the refrigerant r134a 1 1 1 2 tetrafluoroethane are given in table ii several control runs with the refrigerant r134a 1 1 1 2.