**sulfur hexafluoride** is an inorganic compound with the formula SF6. It is a gas with a high [dielectric](/resources/glossary/d/) constant (very insulating), so it is commonly used as an insulator in power distribution systems, especially at high voltages. It is also used in some industrial processes in the iron and steel industry and in surgery. Under normal conditions of pressure and temperature, it is a colorless, odorless, non-toxic, non-flammable gas, with the particularity of being five times heavier than air, with a density of 6.13 g/L at one atmosphere of pressure. Learn more in our section: [SF6 handling, recovery and transfer equipment](/products/test-switches/handling-sf6/)