The highest grade of POE refrigeration oil is designed specifically for use with HFC refrigerants. Also miscible with CFC and HCFC refrigerants as well. Due to Polyol Ester Oils natural ability to absorb moisture, acid may be formed in some operating systems possibly causing compressor burnout and/or other component failure. Comstar’s POE oil for A/C Applications, however, is formulated to be less hydroscopic (moisture absorbing) than other brands. In addition, ComStars POE oils have excellent thermal, oxidative and hydrolytic stability thereby reducing compressor wear and eliminating copper plating. ComStar’s POE oil for A/C applications is extremely cost effective as compared to other manufacturers POE oils.