(US5728315-A)      Azeotrope-like compositions comprising trifluoromethane, carbon dioxide, ethane, and hexafluoroethane. The composition boils at -99 2C at 760 mmHg. Also claimed is a premix of a polyol and a blowing agent comprising the above composition. Further claimed is a method for producing foam comprising blending a heat plasticised resin with a volatile blowing agent comprising the above composition and feeding the resin/volatile blowing agent blend into a zone of lower pressure to cause foaming.    USE -   The composition is used for producing polyurethane and polyisocyanurate foams by reacting and foaming a mixture of ingredients that will react to form the polyurethane and polyisocyanurate foams in the presence of a volatile blowing agent comprising the above composition. The compositions are useful for refrigeration by condensing a refrigerant comprising the above composition and then evaporating the refrigerant in the vicinity of a body to be cooled, or for producing heating by condensing a refrigerant comprising the above composition in the vicinity of a body to be heated and then evaporating the refrigerant (all claimed). The compositions are also useful for aerosol propellants and gaseous dielectrics. The compositions are environmentally desirable replacements, e.g. for chlorofluorocarbons (CFC's) and the hydrochlorofluorocarbons (HCFC's), e.g. R-503 (chlorotrifluoromethane and trifluoromethane) which are suspected of causing damage to the ozone layer.    ADVANTAGE -   The compositions have low ozone depletion potential, are negligible contributors to greenhouse global warming, are non-flammable, and have low compressor discharge temperatures. Additionally, the compositions offer superior efficiency and capacity, compared to, e.g. R-23 alone and exhibit constant vapour pressure characteristics and relatively minor composition shifts as the liquid mixture is evaporated, being comparable to a constant boiling single component refrigerant or azeotropic mixture.