Fluorinated gases pharmaceutical industries, as well as in refrigeration when combined with other gases. PFCs were commonly used as fire extinguishants in the past and are still found in older fire protection systems. They are also a by-product of the aluminium smelting process. Sulphur hexafluoride (SF) is used primarily as an insulation gas. It can be found in high-voltage switchgear and is used in the production of magnesium. HFCs were developed in the 1990s to substitute substances such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). As these substances were found to deplete the ozone layer, the Montreal Protocol lays down provisions for them
Montreal Protocol over the period 1991 to 2005. Funds are used, for example, to finance the conversion of existing manufacturing processes, train personnel, pay royalties and patent rights on new technologies, and establish national ozone offices. As of 23 June 2015, all countries in the United Nations, the Cook Islands, Holy See, Niue as well as the European Union have ratified the original Montreal Protocol (see external link below), with South Sudan being the last country to ratify the agreement, bringing the total to 197. These countries have also ratified the London, Copenhagen, Montreal, and Beijing amendments. Since the Montreal Protocol came