In order to reduce migration of plasticizers out of polyvinyl chloride (PVC), several techniques were attempted. First, binary blends of plasticizers were added to PVC, migration was decreased 100 or 1,000 times as compared to PVC samples containing only one plasticizer: the diffusion coefficient was of the order of 10(-8) cm(2) s(-1) for the blend di-2-ethylhexylphthalate (DEHP)/di-2-ethylhexylterephthalate (TDHP) or 10(-9) cm(2) s(-1) for the blend DEHP/DBP. A thermal treatment of PVC samples containing only one plasticizer leads to diffusion coefficients of the order of 10(-10) cm(2) s(-1). This second method was also applied to PVC samples plasticized with binary blends. It lowers even more migration of both plasticizers out of PVC. But no particular phenomena were observed with ternary blends of plasticizers introduced in PVC.