Production of chlorofluorocarbons (CFCs) has been phased out. Environmentally acceptable replacement compounds are therefore needed for use in existing medium and low temperature refrigeration applications. Refrigerant R134a or HFC-134a was developed to meet these needs. Refrigerant R134a or HFC-134a is a commercially available hydrofluorocarbon (HFC) refrigerant for use as a long-term replacement for R-12 in new equipment and for retrofitting medium temperature CFC-12 systems.(