The guidance developed by the OECD and experience gained by OECD countries provide useful reference in this regard. In addition to action on chlorofluorocarbons, Colombia took steps to control the use of hydrochlorofluorocarbons (HCFCs) in advance of the relevant international agreement. Further efforts are needed to curtail the continued illegal import of banned substances and to manage the collection and environmentally sound disposal of ozone-depleting substances contained in equipment still in use.