Sulfur hexafluoride, also known as sulfur(VI) fluoride, is a chemical compound. Its chemical formula is SF₆. It contains sulfur in its +6 oxidation state. It also contains fluoride ions.

BBC News says "It's the most powerful greenhouse gas known to humanity, and emissions have risen rapidly in recent years. Sulphur hexafluoride, or SF6, is widely used in the electrical industry to prevent short circuits and accidents. Leaks of the little-known gas in the UK and the rest of the EU in 2017 were the equivalent of putting an extra 1.3 million cars on the road".