The number of single component refrigerants with different thermodynamic properties suitable for different types of equipment is limited. Growing demand for refrigeration and air-conditioning with diversified applications has led to a continued search for suitable refrigerant blends. A number of such blends have been developed by mixing two or more single component refrigerants in different proportions. The resulting blend, has entirely different properties from that of its components. While it is common to use the term ‘blends’ in the context of the Montreal Protocol, it is important to note that the term ‘mixtures’ is also used to describe refrigerants which are comprised of more than one component. The terminology ‘mixtures’ is specifically used in the World Customs Organization classification Harmonized Commodity Description and Coding System, also known as the Harmonized System (i.e. HS codes).