The EPS manufacturing process unlike many synthetic materials does not involved the use of ozone-layer-depleting CFCs and HCFCs, nor are there harmful materials present in the finished product.
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 molded 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.
No residual solid waste is generated during its manufacture as EPS is uniquely recyclable – all manufacturing waste can be completely reprocessed in the production process.
EPS is an excellent example of an efficient use of a natural resource as the transformation process uses relatively little energy.