Enamel VS Plastic which one is not toxic and can be kept in the refrigerator?

Enamel cups are made after thousands of degrees of high temperature enameling, does not contain lead and other harmful substances, easy to carry and clean. Enamel cups are usually coated with a layer of glaze on the inner wall, when the cups are filled with boiling water or acid, alkaline beverages, some of the glaze in the aluminum and other heavy metal elements are easy to precipitate and dissolve into the liquid, endangering human health. Therefore, the use of enamel cups is best to choose the color of the cup, do not choose the cup coated with colored glaze. Plastic cups because of its varied shape, bright colors, not afraid of the characteristics of the drop, by many people's favorite. In fact, plastic belongs to the polymer chemical materials, often containing polypropylene ethylene or PVC PVC and other toxic chemicals, plastic cups loaded with hot water or boiling water, these toxic chemicals can easily precipitate into the water. And plastic cups are prone to bacteria, not easy to wash, because the surface of the plastic looks smooth, in fact, its internal microstructure has a lot of pores, easy to hide dirt.