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Sulfur hexafluoride or sulphur hexafluoride ( British spelling) is an
inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...
with the formula SF6. It is a colorless, odorless, non-
flammable A combustible material is a material that can burn (i.e., sustain a flame) in air under certain conditions. A material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort ...
, and non-toxic gas. has an octahedral geometry, consisting of six
fluorine Fluorine is a chemical element; it has Chemical symbol, symbol F and atomic number 9. It is the lightest halogen and exists at Standard temperature and pressure, standard conditions as pale yellow Diatomic molecule, diatomic gas. Fluorine is extre ...
atoms attached to a central
sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...
atom. It is a hypervalent molecule. Typical for a nonpolar gas, 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. has 23,500 times greater
global warming potential Global warming potential (GWP) is a measure of how much heat a greenhouse gas traps in the atmosphere over a specific time period, relative to carbon dioxide (). It is expressed as a multiple of warming caused by the same mass of carbon dioxide ( ...
(GWP) than as a
greenhouse gas Greenhouse gases (GHGs) are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. Unlike other gases, greenhouse gases absorb the radiations that a planet emits, resulting in the greenhouse effect. T ...
(over a 100-year time-frame) but exists in relatively minor concentrations in the atmosphere. Its concentration in Earth's
troposphere The troposphere is the lowest layer of the atmosphere of Earth. It contains 80% of the total mass of the Atmosphere, planetary atmosphere and 99% of the total mass of water vapor and aerosols, and is where most weather phenomena occur. From the ...
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 gas contained in its medium- and high-voltage
switchgear In an electric power system, a switchgear is composed of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to ...
. Uses in magnesium, aluminium, and electronics manufacturing also hastened atmospheric growth. The 1997
Kyoto Protocol The was an international treaty which extended the 1992 United Nations Framework Convention on Climate Change (UNFCCC) that commits state parties to reduce greenhouse gas emissions, based on the scientific consensus that global warming is oc ...
, 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 Carbon emission trading (also called carbon market, emission trading scheme (ETS) or cap and trade) is a type of emissions trading scheme designed for carbon dioxide (CO2) and other greenhouse gases (GHGs). A form of carbon pricing, its purpose ...
scheme. In some countries this has led to the defunction of entire industries.


Synthesis and reactions

Sulfur hexafluoride on Earth exists primarily as a synthetic industrial gas, but has also been found to occur naturally. can be prepared from the elements through exposure of to . This was the method used by the discoverers Henri Moissan and Paul Lebeau in 1901. Some other sulfur fluorides are cogenerated, but these are removed by heating the mixture to disproportionate any (which is highly toxic) and then scrubbing the product with NaOH to destroy remaining . Alternatively, using
bromine Bromine is a chemical element; it has chemical symbol, symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between th ...
, sulfur hexafluoride can be synthesized from SF4 and CoF3 at lower temperatures (e.g. 100 °C), as follows: There is virtually no reaction chemistry for . A main contribution to the inertness of SF6 is the
steric hindrance Steric effects arise from the spatial arrangement of atoms. When atoms come close together there is generally a rise in the energy of the molecule. Steric effects are nonbonding interactions that influence the shape ( conformation) and reactivi ...
of the sulfur atom, whereas its heavier group 16 counterparts, such as SeF6 are more reactive than SF6 as a result of less steric hindrance. It does not react with molten
sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...
below its boiling point, but reacts exothermically with
lithium Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the ...
. As a result of its inertness, has an atmospheric lifetime of around 3200 years, and no significant environmental sinks other than the ocean.


Applications

By 2000, the
electrical power industry Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwel ...
is estimated to use about 80% of the sulfur hexafluoride produced, mostly as a gaseous dielectric medium. Other main uses as of 2015 included a silicon etchant for
semiconductor manufacturing Semiconductor device fabrication is the process used to manufacture semiconductor devices, typically integrated circuits (ICs) such as microprocessors, microcontrollers, and memories (such as Random-access memory, RAM and flash memory). It is a ...
, and an
inert gas An inert gas is a gas that does not readily undergo chemical reactions with other chemical substances and therefore does not readily form chemical compounds. Though inert gases have a variety of applications, they are generally used to prevent u ...
for the casting of
magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...
.


Dielectric medium

is used in the electrical industry as a gaseous dielectric medium for high-voltage sulfur hexafluoride circuit breakers,
switchgear In an electric power system, a switchgear is composed of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to ...
, and other
electrical Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwel ...
equipment, often replacing oil-filled circuit breakers (OCBs) that can contain harmful polychlorinated biphenyls (PCBs). gas under
pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and eve ...
is used as an insulator in gas insulated switchgear (GIS) because it has a much higher dielectric strength than
air An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...
or dry
nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...
. The high dielectric strength is a result of the gas's high
electronegativity Electronegativity, symbolized as , is the tendency for an atom of a given chemical element to attract shared electrons (or electron density) when forming a chemical bond. An atom's electronegativity is affected by both its atomic number and the ...
and
density Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be u ...
. This property makes it possible to significantly reduce the size of electrical gear. This makes GIS more suitable for certain purposes such as indoor placement, as opposed to air-insulated electrical gear, which takes up considerably more room. Gas-insulated electrical gear is also more resistant to the effects of pollution and climate, as well as being more reliable in long-term operation because of its controlled operating environment. Exposure to an arc chemically breaks down though most of the decomposition products tend to quickly re-form , a process termed "self-healing". Arcing or corona can produce disulfur decafluoride ( ), a highly
toxic Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subst ...
gas, with toxicity similar to
phosgene Phosgene is an organic chemical compound with the formula . It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut hay or grass. It can be thought of chemically as the double acyl chloride analog of ...
. was considered a potential chemical warfare agent in
World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
because it does not produce lacrimation or skin irritation, thus providing little warning of exposure. is also commonly encountered as a high voltage dielectric in the high voltage supplies of
particle accelerator A particle accelerator is a machine that uses electromagnetic fields to propel electric charge, charged particles to very high speeds and energies to contain them in well-defined particle beam, beams. Small accelerators are used for fundamental ...
s, such as
Van de Graaff generator A Van de Graaff generator is an electrostatic generator which uses a moving belt to accumulate electric charge on a hollow metal globe on the top of an insulated column, creating very high electric potentials. It produces very high voltage direct ...
s and Pelletrons and high voltage transmission
electron microscope An electron microscope is a microscope that uses a beam of electrons as a source of illumination. It uses electron optics that are analogous to the glass lenses of an optical light microscope to control the electron beam, for instance focusing it ...
s. Alternatives to as a dielectric gas include several fluoroketones. Compact GIS technology that combines vacuum switching with clean air insulation has been introduced for a subset of applications up to 420  kV.


Medical use

is used to provide a tamponade or plug of a retinal hole in retinal detachment repair operations in the form of a gas bubble. It is inert in the vitreous chamber. The bubble initially doubles its volume in 36 hours due to oxygen and nitrogen entering it, before being absorbed in the blood in 10–14 days. is used as a contrast agent for
ultrasound Ultrasound is sound with frequency, frequencies greater than 20 Hertz, kilohertz. This frequency is the approximate upper audible hearing range, limit of human hearing in healthy young adults. The physical principles of acoustic waves apply ...
imaging. Sulfur hexafluoride microbubbles are administered in solution through injection into a peripheral vein. These microbubbles enhance the visibility of blood vessels to ultrasound. This application has been used to examine the vascularity of tumours. It remains visible in the blood for 3 to 8 minutes, and is exhaled by the lungs.


Tracer compound

Sulfur hexafluoride was the tracer gas used in the first roadway air dispersion model calibration; this research program was sponsored by the U.S. Environmental Protection Agency and conducted in
Sunnyvale, California Sunnyvale () is a city located in the Santa Clara Valley in northwestern Santa Clara County, California, United States. Sunnyvale lies along the historic El Camino Real (California), El Camino Real and U.S. Route 101 in California, Highway 1 ...
on U.S. Highway 101. Gaseous is used as a tracer gas in short-term experiments of
ventilation Ventilation may refer to: * Ventilation (physiology), the movement of air between the environment and the lungs via inhalation and exhalation ** Mechanical ventilation, in medicine, using artificial methods to assist breathing *** Respirator, a ma ...
efficiency in buildings and indoor enclosures, and for determining infiltration rates. Two major factors recommend its use: its concentration can be measured with satisfactory accuracy at very low concentrations, and the
Earth's atmosphere The atmosphere of Earth is composed of a layer of gas mixture that surrounds the Earth's planetary surface (both lands and oceans), known collectively as air, with variable quantities of suspended aerosols and particulates (which create weathe ...
has a negligible concentration of . Sulfur hexafluoride was used as a non-toxic test gas in an experiment at St John's Wood tube station in
London London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...
, United Kingdom on 25 March 2007. The gas was released throughout the station, and monitored as it drifted around. The purpose of the experiment, which had been announced earlier in March by the
Secretary of State for Transport The secretary of state for transport, also referred to as the transport secretary, is a Secretary of State (United Kingdom), secretary of state in the Government of the United Kingdom, with overall responsibility for the policies of the Departm ...
Douglas Alexander, was to investigate how toxic gas might spread throughout
London Underground The London Underground (also known simply as the Underground or as the Tube) is a rapid transit system serving Greater London and some parts of the adjacent home counties of Buckinghamshire, Essex and Hertfordshire in England. The Undergro ...
stations and buildings during a terrorist attack. Sulfur hexafluoride is also routinely used as a tracer gas in laboratory fume hood containment testing. The gas is used in the final stage of
ASHRAE The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE ) is an American professional association seeking to advance heating, ventilation, air conditioning and refrigeration (HVAC&R) systems design and constructio ...
110 fume hood qualification. A plume of gas is generated inside of the fume hood and a battery of tests are performed while a gas analyzer arranged outside of the hood samples for SF6 to verify the containment properties of the fume hood. It has been used successfully as a transient tracer in
oceanography Oceanography (), also known as oceanology, sea science, ocean science, and marine science, is the scientific study of the ocean, including its physics, chemistry, biology, and geology. It is an Earth science, which covers a wide range of to ...
to study diapycnal mixing and air-sea gas exchange. The concentration of sulfur hexafluoride in seawater (typically on the order of femtomoles per kilogram) has been classified by the international oceanography community as a "level one" measurement, denoting the highest priority data for observing ocean changes.


Other uses

* The
magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...
industry uses as an inert "cover gas" to prevent oxidation during
casting Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a casting, which is ejected or ...
, and other processes including smelting. Once the largest user, consumption has declined greatly with capture and recycling. * Insulated glazing windows have used it as a filler to improve their thermal and acoustic insulation performance. * plasma is used in the
semiconductor A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping level ...
industry as an etchant in processes such as
deep reactive-ion etching Deep reactive-ion etching (DRIE) is a special subclass of reactive-ion etching (RIE). It enables highly anisotropy, anisotropic etching (microfab), etch process used to create deep penetration, steep-sided holes and trenches in wafer (semiconducto ...
. A small fraction of the breaks down in the plasma into sulfur and fluorine, with the fluorine ions performing a chemical reaction with silicon. * Tires filled with it take longer to deflate from
diffusion Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical p ...
through rubber due to the larger molecule size. * Nike likewise used it to obtain a
patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling discl ...
and to fill the cushion bags in all of their "Air"-branded shoes from 1992 to 2006. 277 tons was used during the peak in 1997. * The
United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...
's Mark 50 torpedo closed Rankine-cycle propulsion system is powered by sulfur hexafluoride in an
exothermic reaction In thermochemistry, an exothermic reaction is a "reaction for which the overall standard enthalpy change Δ''H''⚬ is negative." Exothermic reactions usually release heat. The term is often confused with exergonic reaction, which IUPAC define ...
with solid
lithium Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the ...
. * Waveguides in high-power
microwave Microwave is a form of electromagnetic radiation with wavelengths shorter than other radio waves but longer than infrared waves. Its wavelength ranges from about one meter to one millimeter, corresponding to frequency, frequencies between 300&n ...
systems are pressurized with it. The gas electrically insulates the waveguide, preventing internal arcing. * Electrostatic loudspeakers have used it because of its high dielectric strength and high molecular weight. * Disulfur decafluoride, a
chemical weapon A chemical weapon (CW) is a specialized munition that uses chemicals formulated to inflict death or harm on humans. According to the Organisation for the Prohibition of Chemical Weapons (OPCW), this can be any chemical compound intended as ...
, is produced with it as a feedstock. * For entertainment purposes, when breathed, causes the voice to become significantly deeper, due to its density being so much higher than air. This phenomenon is related to the more well-known effect of breathing low-density
helium Helium (from ) is a chemical element; it has chemical symbol, symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert gas, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is ...
, which causes someone's voice to become much higher. Both of these effects should only be attempted with caution as these gases displace
oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...
that the lungs are attempting to extract from the air. Sulfur hexafluoride is also mildly anesthetic. * For science demonstrations / magic as "invisible water" since a light foil boat can be floated in a tank, as will an air-filled balloon. *It is used for benchmark and calibration measurements in Associative and Dissociative Electron Attachment (DEA) experiments


Greenhouse gas

File:SF6 mm.png, Sulfur hexafluoride (SF6) measured by the Advanced Global Atmospheric Gases Experiment
AGAGE
in the lower atmosphere (
troposphere The troposphere is the lowest layer of the atmosphere of Earth. It contains 80% of the total mass of the Atmosphere, planetary atmosphere and 99% of the total mass of water vapor and aerosols, and is where most weather phenomena occur. From the ...
) at stations around the world. Abundances are given as pollution free monthly mean mole fractions in parts-per-trillion. File:AGAGE sulfur hexafluroride growth.png, Abundance and growth rate of in Earth's troposphere (1978-2018).Simmonds, P. G., Rigby, M., Manning, A. J., Park, S., Stanley, K. M., McCulloch, A., Henne, S., Graziosi, F., Maione, M., and 19 others (2020) "The increasing atmospheric burden of the greenhouse gas sulfur hexafluoride (SF6)". ''Atmos. Chem. Phys.'', 20: 7271–7290. . Material was copied from this source, which is available under
Creative Commons Attribution 4.0 International License
File:Halogenated gas concentrations 1978-present.png, Atmospheric concentration of SF6 vs. similar man-made gases (right graph). Note the log scale.
According to the
Intergovernmental Panel on Climate Change The Intergovernmental Panel on Climate Change (IPCC) is an intergovernmental body of the United Nations. Its job is to "provide governments at all levels with scientific information that they can use to develop climate policies". The World Met ...
, is the most potent
greenhouse gas Greenhouse gases (GHGs) are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. Unlike other gases, greenhouse gases absorb the radiations that a planet emits, resulting in the greenhouse effect. T ...
. Its
global warming potential Global warming potential (GWP) is a measure of how much heat a greenhouse gas traps in the atmosphere over a specific time period, relative to carbon dioxide (). It is expressed as a multiple of warming caused by the same mass of carbon dioxide ( ...
of 23,900 times that of when compared over a 100-year period. Sulfur hexafluoride is inert in the
troposphere The troposphere is the lowest layer of the atmosphere of Earth. It contains 80% of the total mass of the Atmosphere, planetary atmosphere and 99% of the total mass of water vapor and aerosols, and is where most weather phenomena occur. From the ...
and
stratosphere The stratosphere () is the second-lowest layer of the atmosphere of Earth, located above the troposphere and below the mesosphere. The stratosphere is composed of stratified temperature zones, with the warmer layers of air located higher ...
and is extremely long-lived, with an estimated atmospheric lifetime of 800–3,200 years. Measurements of SF6 show that its global average
mixing ratio In chemistry and physics, the dimensionless mixing ratio is the abundance of one component of a mixture relative to that of all other components. The term can refer either to mole ratio (see concentration) or mass ratio (see stoichiometry). In a ...
has increased from a steady base of about 54 parts per quadrillion prior to industrialization, to over 12 parts per trillion (ppt) as of February 2025, and is increasing by about 0.4 ppt (3.5%) per year. Average global SF6 concentrations increased by about 7% per year during the 1980s and 1990s, mostly as the result of its use in
magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...
production, and by electrical utilities and electronics manufacturers. Given the small amounts of SF6 released compared to
carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...
, its overall individual contribution to global warming is estimated to be less than 0.2%, however the collective contribution of it and similar man-made halogenated gases has reached about 10% as of 2020. Alternatives are being tested. In Europe, falls under the F-Gas directive which ban or control its use for several applications. Since 1 January 2006, is banned as a tracer gas and in all applications except high-voltage switchgear. It was reported in 2013 that a three-year effort by the
United States Department of Energy The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and energy production, the research and development of nuclear power, the military's nuclear w ...
to identify and fix leaks at its laboratories in the United States such as the
Princeton Plasma Physics Laboratory Princeton Plasma Physics Laboratory (PPPL) is a United States Department of Energy national laboratory for plasma physics and nuclear fusion science. Its primary mission is research into and development of fusion as an energy source. It is know ...
, where the gas is used as a high voltage insulator, had been productive, cutting annual leaks by . This was done by comparing purchases with inventory, assuming the difference was leaked, then locating and fixing the leaks.


Physiological effects and precautions

Sulfur hexafluoride is a nontoxic gas, but by displacing oxygen in the lungs, it also carries the risk of
asphyxia Asphyxia or asphyxiation is a condition of deficient supply of oxygen to the body which arises from abnormal breathing. Asphyxia causes generalized hypoxia, which affects all the tissues and organs, some more rapidly than others. There are m ...
if too much is inhaled. Since it is more dense than air, a substantial quantity of gas, when released, will settle in low-lying areas and present a significant risk of asphyxiation if the area is entered. That is particularly relevant to its use as an insulator in electrical equipment since workers may be in trenches or pits below equipment containing . As with all gases, the density of affects the resonance frequencies of the vocal tract, thus changing drastically the vocal sound qualities, or
timbre In music, timbre (), also known as tone color or tone quality (from psychoacoustics), is the perceived sound of a musical note, sound or tone. Timbre distinguishes sounds according to their source, such as choir voices and musical instrument ...
, of those who inhale it. It does not affect the vibrations of the vocal folds. The density of sulfur hexafluoride is relatively high at room temperature and pressure due to the gas's large
molar mass In chemistry, the molar mass () (sometimes called molecular weight or formula weight, but see related quantities for usage) of a chemical substance ( element or compound) is defined as the ratio between the mass () and the amount of substance ...
. Unlike
helium Helium (from ) is a chemical element; it has chemical symbol, symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert gas, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is ...
, which has a molar mass of about 4 g/mol and pitches the voice up, has a molar mass of about 146 g/mol, and the speed of sound through the gas is about 134 m/s at room temperature, pitching the voice down. For comparison, the molar mass of air, which is about 80% nitrogen and 20% oxygen, is approximately 30 g/mol which leads to a speed of sound of 343 m/s. Sulfur hexafluoride has an anesthetic potency slightly lower than
nitrous oxide Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or factitious air, among others, is a chemical compound, an Nitrogen oxide, oxide of nitrogen with the Chemical formula, formula . At room te ...
; it is classified as a mild anesthetic.


See also

* Selenium hexafluoride * Tellurium hexafluoride * Uranium hexafluoride * Hypervalent molecule * Halocarbon—another group of major greenhouse gases * Trifluoromethylsulfur pentafluoride, a similar gas


References


Further reading

* * * * *
SF6 Reduction Partnership for Electric Power Systems
*


External links



�� National Pollutant Inventory
High GWP Gases and Climate Change
from the U.S. EPA website
International Conference on SF6 and the Environment


{{DEFAULTSORT:Sulfur Hexafluoride Sulfur fluorides Dielectric gases Greenhouse gases Octahedral compounds Hexafluorides Industrial gases Refrigerants Hypervalent molecules General anesthetics Ultrasound contrast agents