In order to expand polystyrene, steam is applied to tiny grains of styrene that contain a minute amount of pentane. The expanded beads are then moulded into a shape or a large block which is then sliced into boards. The minuscule amount of pentane gas used in the process has no known effect on the upper ozone layer.

Any in-house waste EPS produced during the manufacturing process can be reground and incorporated as recyclate into a variety of products such as EPS moulded blocks and also void forms such as EPS pods. 

EPS is an excellent example of an efficient use of a natural resource as the transformation process uses very little energy.