Disclosed is a non-flammable refrigerant composition consisting of pentafluoroethane in an amount from 62% to 67% based on the weight of the composition; a second component selected from 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, and mixtures thereof in an amount from 26% to 36% by weight based on the weight of the composition; and an ethylenically unsaturated or saturated hydrocarbon compound that is at least 80% isobutane in an amount of from 3% to 4% by weight of the composition. Optionally, the composition may include at least one lubricant, at least one additive or combinations thereof.