Sulfur hexafluoride (SF6) or sulphur hexafluoride (British spelling) is an extremely potent and persistent greenhouse gas that is primarily utilized as an electrical insulator and arc suppressant. It is inorganic, colorless, odorless, non-flammable, and non-toxic. SF6 has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom. It is a hypervalent molecule.

Typical for a nonpolar gas, SF6 is poorly soluble in water but quite soluble in nonpolar organic solvents. It has a density of 6.12 g/L at sea level conditions, considerably higher than the density of air (1.225 g/L). It is generally transported as a liquefied compressed gas.

The concentration of SF6 in Earth's troposphere reached 10 parts per trillion (ppt) in year 2019, rising at 0.35 ppt/year. The increase over the prior 40 years was driven in large part by the expanding electric power sector, including fugitive emissions from banks of SF6 gas contained in its medium- and high-voltage switchgear. Uses in magnesium, aluminium, and electronics manufacturing also hastened atmospheric growth.

 

Note:   The above text is excerpted from the Wikipedia article Sulfur hexafluoride, which has been released under the GNU Free Documentation License.