This project was performed to identify and quantify the typical contaminant levels in used refrigerant samples obtained from Refrigerant 11 systems, from Refrigerant 12 commercial refrigeration systems, from Refrigerant 22 air conditioners and heat pumps, and from Refrigerant 502 low temperature frozen food cases. The operating conditions of the sampled systems ranged from normal operating systems (minimal refrigerant contamination) to systems requiring minimal repair (average refrigerant contamination) to systems experiencing motor burnouts (severe refrigerant contamination). The obtained refrigerant samples were analyzed for water, acid, high boiling residue, volatile impurity and particulate contents. Synthetic refrigerants were then formulated based on the levels and types of contamination present in the used refrigerants. The synthetic refrigerants were used to make a preliminary evaluation of refrigerant recycling techniques. The results of this research will be used as the initial step in establishing quality standards for evaluating present and future recycling equipment and techniques.