Disposal methods, health effects and emission regulations for sulfur hexafluoride and its by-products

Highlights: • Sulfur hexafluoride is the most potent greenhouse gas with toxic by-products. • The lack of disposal avenues for the end-of-life SF₆ is contributing emissions. • The non-thermal plasma decomposition of SF6 is more efficient than incineration. • The handling of SF₆ must adhere to the Kyoto Protocol and IEC standards. Sulfur hexafluoride (SF₆) is the most potent greenhouse gas contributed by the power and semiconductor industries. The global emissions of gas in the past 10 years have increased tremendously due to lack of disposal routes. This was brought to 190 nations' attention in the Kyoto Protocol for the need of emission control measures to reduce its impacts of climate change and global warming. Various novel techniques have surfaced to tackle this issue, such as non-thermal plasma (NTP) which includes radio frequency plasma, microwave plasma, dielectric barrier discharge, and electron beam. The main by-products resulting from the decomposition of SF₆ by these techniques are sulfur oxyfluorides, sulfur dioxide, hydrofluoric acid, and fluorine gas. This environmental and health effects as well as global emission of SF₆ gas are considered a threat to humans and the climate, where modern disposal methods of contaminated SF₆ gas and its by-products should replace the conventional approaches. Relevant government policies on the safety and disposal concern of SF₆ gas are reviewed and challenges and further research directions for the disposal of SF₆ gas are highlighted in this review article.