Rikkiheksafluoridi

Rikkiheksafluoridi, known in English as sulfur hexafluoride (SF6), is a chemical compound consisting of one sulfur atom surrounded by six fluorine atoms. It is a colorless, odorless, non-flammable gas at room temperature and is highly inert due to the strength of the sulfur–fluorine bonds.

Properties and characteristics

SF6 has a molecular weight of 146.05 g/mol and adopts an octahedral structure. Its boiling point is about −64 °C, and at ambient conditions it remains a gas. The gas is extremely dense for a nonpolar substance, with a density around 6 g/L at standard conditions, making it several times heavier than air. It is chemically very stable, non-toxic in short-term exposure, and has excellent electrical insulation properties, which explains its widespread use in electrical equipment. However, asphyxiation is a risk if it displaces oxygen in confined spaces. SF6 is also a potent greenhouse gas with a long atmospheric lifetime and a high global warming potential.

Production and applications

SF6 is produced industrially by direct fluorination of sulfur with fluorine gas. Its primary use is as an insulating and arc-quenching gas in high-voltage switchgear, circuit breakers, and transformers. It is valued for its dielectric strength and arc-suppression performance. SF6 is also used as a tracer gas for leak testing and, at trace concentrations, as a contrast agent in certain medical ultrasound applications.

Environmental and safety considerations

Because of its very high global warming potential and long atmospheric lifetime, emissions of SF6 are tightly regulated in many regions, and there is emphasis on recovering, recycling, and minimizing leaks. Alternatives and SF6-free technologies are promoted to reduce climate impact. Handling requires good ventilation, proper equipment integrity, and adherence to safety guidelines to prevent asphyxiation risks in enclosed spaces.