Sulfur hexafluoride

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; Sulfuryl fluoride; Tellurium hexafluoride; Polonium hexafluoride
	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-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.