The focus on the ozone layer of the stratosphere as well as how this is threatened by discharge of CFC has achieved importance for the production of several products, among others foamed polystyrene for insulating purposes. In road construction connections this first and foremost concerns insulating boards of extruded polystyrene (XPS) and to a certain extent polyethylene foam (PE-foam). CFC has traditionally been used as foaming agent in the production of such materials. In UN's Montreal protocol for protection of the ozone layer the CFC gases are ranged in assumed order of dangerousness for the ozone layer, and a time for removing these gases has been agreed on. The Montreal protocol will be renegotiated at the end of 1992, and it is assumed that the time allowed for removing the CFC will be considerably accelerated.
Samenvatting