One of the most widely used plastics, polystyrene is used a great deal in foams, molded products, and sheet materials because of its rigidity, its ability to be molded and extruded, and its desirable electrical and physical insulating properties, as well as its recyclability, and its flexibility to be either transparent or take on various colors. We are including the word here as polystyrene is often used in various forms in the building and furnishings industries.