We can rely on the naked eye and feel to buy plastic wrap, PE cling film viscosity and poor transparency than PVC cling film, after the hand rub easy to open, and PVC cling film is easier to stick to your hands, PVDC little sticky, not Flexible, easily broken. We can also use a lighter to ignite plastic wrap to identify, dripping like wax, like plastic wrap if burning candles and exudes a smell, after leaving the fire source can continue to burn, that is non-toxic polyethylene PE film; and there are PVC combustion unpleasant pungent taste, black smoke, because the chlorine in PVC combustion released out; the flame self-extinguishing PVDC difficult to burn, remove the source of fire, the flame was yellow-green , pungent odor.