Sulfur Hexafluoride (SF6) Emission Reductions from the Electricity Sector and Particle Accelerators

This page last reviewed December 12, 2011


Sulfur hexafluoride (SF6) is a highly potent greenhouse gas.  Over a 100-year period, SF6 is 23,900 times more effective at trapping infrared radiation than an equivalent amount of carbon dioxide.  SF6 is also a very stable chemical, with an atmospheric lifetime of 3,200 years.

The most common use for SF6 is as an electrical insulator in high-voltage equipment that transmits and distributes electricity.  Since the 1950’s, the U.S. electric power industry has used SF6 widely in circuit breakers, gas-insulated substations, and other switchgear used in the transmission system to manage the high voltages carried between generation stations and customer load centers.  Fugitive emissions of SF6 can escape from gas insulated substations and switchgear through seals.  It can also be released during equipment installation and when equipment is opened for servicing.  Several factors affect SF6 emissions from electric power systems, such as the type and age of the equipment (e.g., older circuit breakers can contain up to 2,000 pounds of SF6, while modern breakers usually contain less than 100 pounds) and the handling and maintenance procedures practiced by the utilities.