Disclosed is a method for treating a surface of a PVC product. A PVC product including PVC and plasticizer is provided. A surface of the PVC product is treated by an aqueous solution of a crosslinking agent and a first phase transfer catalyst to form a first surface treated PVC product. The surface of the first surface treated PVC product is treated by an aqueous solution of an aqueous free radical initiator and a second phase transfer catalyst to form a second surface treated PVC product. As such, the release of the plasticizer from the PVC product to an environment is inhibited.