It is absolutely essential to reduce the amount of oil we consume. Although polystyrene is an oil-based product, only an extraordinarily small amount of this precious natural resource is required to produce it. This is because expanded polystyrene (EPS) effectively consists of 98 % air and only 2 % polystyrene, the cells which contain the air. For every litre of oil that is used to manufacture EPS building insulation, up to 200 litres of heating oil is saved over the life of the product. Thus, there is almost no better use for oil than the production of insulating material!