Abstract: This invention relates to compositions that include nitrous oxide and at least one of trifluoromethane, difluoromethane, tetrafluoroethane, pentafluoroethane, perfluoroethane or ethane. These compositions are useful as refrigerants, cleaning agents, expansion agents for polyolefins and polyurethanes, refrigerants, aerosol propellants, heat transfer media, electronic gases, plasma etchants, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, and displacement drying agents.