Sulfur hexafluoride

Sulfur hexafluoride
Skeletal formula of sulfur hexafluoride with assorted dimensions	Spacefill model of sulfur hexafluoride
	Ball and stick model of sulfur hexafluoride
Names
	IUPAC name Sulfur hexafluoride
	Systematic IUPAC name Hexafluoro-λ6-sulfane
	Other names Elagas; Esaflon; Sulfur(VI) fluoride; Sulfuric fluoride;
Identifiers
CAS Number	2551-62-4 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:30496 ;
ChemSpider	16425 ;
ECHA InfoCard	100.018.050
EC Number	219-854-2;
Gmelin Reference	2752
KEGG	D05962 ;
MeSH	Sulfur+hexafluoride
PubChem CID	17358;
RTECS number	WS4900000;
UNII	WS7LR3I1D6 ;
UN number	1080
CompTox Dashboard (EPA)	DTXSID8029656 ;
	InChI InChI=1S/F6S/c1-7(2,3,4,5)6 Key: SFZCNBIFKDRMGX-UHFFFAOYSA-N ;
	SMILES FS(F)(F)(F)(F)F;
Properties
Chemical formula	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
Solubility in water	0.003% (25 °C)
Solubility	slightly soluble in water, very soluble in ethanol, hexane, benzene
Vapor pressure	2.9 MPa (at 21.1 °C)
Magnetic susceptibility (χ)	−44.0×10−6 cm3/mol
Thermal conductivity	13.45 mW/(m·K) at 25 °C; 11.42 mW/(m·K) at 0 °C;
Viscosity	15.23 μPa·s
Structure
Crystal structure	Orthorhombic, oP28
Space group	Oh
Coordination geometry	Orthogonal hexagonal
Molecular shape	Octahedral
Dipole moment	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
ATC code	V08DA05 (WHO)
License data	EU EMA: by sulphur hexafluoride;
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H280
Precautionary statements	P403
NFPA 704 (fire diamond)	1 0 0 SA
	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; Sulfur tetrafluoride;
Related compounds	Selenium hexafluoride; Tellurium hexafluoride; Polonium hexafluoride; Sulfuryl fluoride; Thionyl tetrafluoride; Sulfur chloride pentafluoride; Pentafluorosulfur hypofluorite; Trifluoromethylsulfur pentafluoride;
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) 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 horizon), but exists in relatively minor concentrations in the atmosphere. Its GWP is 35,000 on a 500-year time horizon, compared with CO₂. 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.