Sulphur hexafluoride – SF6 – is widely used in the electricity distribution industry in medium- and high-voltage installations such as substations, transformers and power stations. It is an odourless, colourless, non-flammable gas that acts as an insulator and prevents explosions and fires brought about by short circuits.
These qualities have made it the most common gas insulator for HV switchgear and use is increasing as a greater number of smaller generators come onto the grid. However, concern has been raised about the global warming potential of SF6 as use increases, perversely driven by increased demand for renewable energy.