Sulfur hexafluoride, its properties and use

Sulfur hexafluoride is a virtually nonreactive gas under normal conditions, slightly soluble in nonpolar solvents. It is produced in amounts up to 10 000 t/year by the reaction of sulfur with gaseous fluorine. Its main use is as a protecting atmosphere in magnesium metallurgy. Due to its high dielectric strength and its ability to quench electric discharges, it is used. as a filling for high-voltage devices. In electric discharges, it partly decomposes to other sulfur fluorides, fluorine and, in the presence of impurities, to sulfur fluoride-oxides, hydrogen fluoride and other corrosive substances. Exhalations of SF6 in atmosphere do not represent any extraordinary danger for the time being, either for the ozone layer or due to the greenhouse effect. In stratosphere, however, its occurrence was observed and hence the long-term monitoring and checking of its emissions is necessary.