Previously presented migration data on the systems poly(vinyl chloride) (PVC)/labeled dioctyl phthalate (DOP)/white spirit, kerosene, white oil, or lubricating oil are now combined with liquid penetration results. Liquid penetration was found to be significant for the lighter oils, while the white oil and the lubricating oil practically seem not to penetrate at all. In accordance with previous investigators this penetration phenomenon was proved to consist of a sorption step up to a point, followed by a desorption step. Both steps were considered separately but the desorption data failed to fit the short-term Fickian approximation. On the other hand, in order to explain the minimum observed of the migration equilibrium values as temperature increase, polymer structure rearrangement to a more compact scheme at the later stages of the immersion experiment is proposed. For this rearrangement, both temperature and liquid penetration seem to comprise contributing factors.