Diffusion coefficients of 1,2-dichloroethane, 1,1,2-trichloroethylene, 1,1,2,2-tetrachloroethane, and carbon tetrachloride into neoprene, SBR, EPDM, NBR, and natural rubber have been obtained from sorption experiments in the temperature interval of 25-degrees to 60-degrees-C. Diffusion was found to be dependent on the type and nature of the barrier material in addition to the diffusant size. The mechanism of diffusion appears to follow the anomalous diffusion. Activation energies for diffusion have been estimated and used in the discussion of transport data. Equilibrium sorption data were used to calculate the enthalpy and entropy of sorption for polymer-solvent pairs.