Disclosed is a nonflammable refrigerant composition consisting of pentafluoroethane in an amount from 62% to 67% based on the weight of the composition, a second component that is selected from 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, and mixtures thereof in an amount from 26% to 36% by weight; and an ethylenically unsaturated or saturated hydrocarbon compound that is at least 70% isobutane in an amount of from 1% to 4% by weight and up to 5% by weight based on the weight of the composition of another fluorohydrocarbon. The composition optionally may further include at least one additive, lubricant or combination thereof.