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
The Fourth Protocol (film) The Fourth Protocol (film) The Fourth Protocol is a 1987 British Cold War spy film featuring Michael Caine and Pierce Brosnan, based on the novel "The Fourth Protocol" by Frederick Forsyth. In 1968, an East-West agreement is established to halt nuclear proliferation. One of its clauses, the Fourth Protocol, forbids the non-conventional delivery of a nuclear weapon to a target. MI5 officer John Preston (Michael Caine) breaks into the residence of British government official George Berenson (Anton Rodgers) on New Year's Eve and finds a number of top secret NATO files that should not have been there. He reports his