Highly-refined, naphthenic refrigeration oils for use with R22 and NH3 refrigerants. Very good flowability at low temperatures ensures continuous heat transfer and enhanced system efficiency of NH3 flooded evaporation systems. High chemical and thermal stability with ammonia. Suitable also for hydrocarbon gases. Fulfills and exceeds DIN 51503 KAA (non-miscible with ammonia), KC and KE. RENISO KC 68 is NSF H2 registered.