Polystyrene: How it’s made, Properties, Uses and The Olden Days

Resin Identification Code, Polystyrene, PS, 6

How is it made?

The most simplified way to explain Polystyrene is: ethylene blended with benzene generate ethylbenzene. Ethylbenzene then goes through a process named dehydrogenation that creates Styrene. Which then proceeds to be polymerised into Polystyrene, PS.


PS is very versatile being able to assume a rigid and a foamed form. It holds moisture for short shelf-life products. The commonly used polystyrene is clear, stiff and brittle. The foamed form is very functional, due to its ratio of rigidity to low density.

Common Uses

Foam PS is used as protective packaging for furniture and electronics, house insulation, disposable foam cups and the famous hinged take away/take out containers also known as clamshell containers.

Rigid PS can serve as cups, plates, bowls, cutlery, meat trays, coat hangers, toys.

Additionally, is used for agricultural trays, video cassette cartridges (remember those?), medical products, and underlay sheeting for laminate flooring.

The Olden Day

In 1839 Eduard Simon discovered Polystyrene which at the time he named it Metastyrol. Later in 1935, Carl Munters and John Tandberg receive a patent for polystyrene foam as a heat insulator. Which paved the way for Otis Ray McIntire and Dow Chemical Company in 1947, when they uncover an improved method to manufacture PS foam, famously know as Styrofoam.

Styrofoam is considered by some to be a nuclear bomb to the ocean.