Sulfur hexafluoride
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| Names | |||
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| IUPAC name
Sulfur hexafluoride | |||
| Systematic IUPAC name
Hexafluoro-λ6-sulfane | |||
| Other names
Elagas Esaflon | |||
| Identifiers | |||
3D model (JSmol) |
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| ChEBI | |||
| ChemSpider | |||
| ECHA InfoCard | 100.018.050 | ||
| EC Number |
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| 2752 | |||
| KEGG | |||
| MeSH | Sulfur+hexafluoride | ||
PubChem CID |
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| RTECS number |
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| UNII | |||
| UN number | 1080 | ||
CompTox Dashboard (EPA) |
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| Properties | |||
| SF6 | |||
| Molar mass | 146.05 g·mol−1 | ||
| Appearance | Colorless gas | ||
| Odor | odorless | ||
| Density | 6.17 g/L | ||
| Melting point | −50.7 °C (−59.3 °F; 222.5 K) (at or above 2,26 bar air pressure - at normal air pressure it sublimes instead) | ||
| Boiling point | −68.25 °C (−90.85 °F; 204.90 K) (sublimes) | ||
| Critical point (T, P) | 45.51±0.1 °C, 3.749±0.01 MPa | ||
| 0.003% (25 °C) | |||
| Solubility | slightly soluble in water, very soluble in ethanol, hexane, benzene | ||
| Vapor pressure | 2.9 MPa (at 21.1 °C) | ||
| −44.0×10−6 cm3/mol | |||
| Thermal conductivity |
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| Viscosity | 15.23 μPa·s | ||
| Structure | |||
| Orthorhombic, oP28 | |||
| Oh | |||
| Orthogonal hexagonal | |||
| Octahedral | |||
| 0 D | |||
| Thermochemistry | |||
Heat capacity (C) |
0.097 kJ/(mol·K) (constant pressure) | ||
Std molar entropy (S⦵298) |
292 J·mol−1·K−1 | ||
Std enthalpy of formation (ΔfH⦵298) |
−1209 kJ·mol−1 | ||
| Pharmacology | |||
| V08DA05 (WHO) | |||
| License data | |||
| Hazards | |||
| GHS labelling: | |||
| Warning | |||
| H280 | |||
| P403 | |||
| NFPA 704 (fire diamond) | |||
| NIOSH (US health exposure limits): | |||
PEL (Permissible) |
TWA 1000 ppm (6000 mg/m3) | ||
REL (Recommended) |
TWA 1000 ppm (6000 mg/m3) | ||
IDLH (Immediate danger) |
N.D. | ||
| Safety data sheet (SDS) | External MSDS | ||
| Related compounds | |||
Related sulfur fluorides |
Disulfur decafluoride | ||
Related compounds |
Selenium hexafluoride Sulfuryl fluoride | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references | |||
Sulfur hexafluoride or sulphur hexafluoride (British spelling) is an inorganic compound with the formula SF6. It is a colorless, odorless, non-flammable, and non-toxic gas. SF
6 has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom. It is a hypervalent molecule.
Typical for a nonpolar gas, SF
6 is poorly soluble in water but quite soluble in nonpolar organic solvents. It has a density of 6.12 g/L at sea level conditions, considerably higher than the density of air (1.225 g/L). It is generally stored and transported as a liquefied compressed gas.
SF
6 has 23,500 times greater global warming potential (GWP) than CO2 as a greenhouse gas (over a 100-year time-frame) but exists in relatively minor concentrations in the atmosphere. Its concentration in Earth's troposphere reached 12.06 parts per trillion (ppt) in February 2025, rising at 0.4 ppt/year. The increase since 1980 is driven in large part by the expanding electric power sector, including fugitive emissions from banks of SF
6 gas contained in its medium- and high-voltage switchgear. Uses in magnesium, aluminium, and electronics manufacturing also hastened atmospheric growth. The 1997 Kyoto Protocol, which came into force in 2005, is supposed to limit emissions of this gas. In a somewhat nebulous way it has been included as part of the carbon emission trading scheme. In some countries this has led to the defunction of entire industries.