A method for measuring the diffusion and solubility of refrigerant-134a in polystyrene is discussed. The static sorption capsule technique was used to obtain data at different temperatures and pressures. By using four capsules in parallel, diffusion coefficients can be obtained. Problems involving low vapor pressure and low solubility are discussed. The solubility data were correlated using Flory-Huggins theory. The technique has been proven reliable upon comparison to literature values.