Air Conditioning Flush removes moisture and particles from air conditioning systems. For use with R134A, R12, and R22. It absorbs and carries moisture from the system as well as trapping and carrying foreign particles from it. It is compatible with all refrigerants and oils. It will not harm o-rings, hoses, PAG, mineral or ester oils. Will not reach with copper, aluminum or brass. It is also biodegradable in its natural state..