Sulfur dioxide

SO₂
CAS Number 7446-09-5
UN1079 (gas)

Molecule
Properties
Applications
Safety & Compatibility
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Liquid / Gas Volumes

Calculate the volume or mass of a quantity of gas or liquid

Liquid Phase

At boiling point at 1.013 bar

m³ (Volume)

kg (Mass)

Gas Phase

In standard conditions (1.013 bar, 15°C)

m³ (Volume)

kg (Mass)

Physical Properties

Download the set of data (XLS - 77.81 KB)

General Properties
Solid Phase
Liquid Phase
Gas Phase

Molecule phase diagram showing the transition phases between solid, liquid and gas as a function of temperature and pressure

Pressure (bar)

- Molar mass 64.064 g/mol
- Content in dry air /
Critical Point
- Temperature 157.60 °C
- Pressure 78.841 bar
- Density 525.11 kg/m³
Triple Point
- Temperature -75.45 °C
- Pressure 1.6744E-2 bar

Pressure 1.013 bar

Latent heat of fusion (at melting point)	115.525 kJ/kg
Melting point	- 73.15 °C

Pressure 1.013 bar

Boiling point	- 10.02 °C
Latent heat of vaporization (at boiling point)	389.06 kJ/kg
Liquid density (at boiling point)	1461.1 kg/m³

Pressure 1.013 bar

0 °C
15 °C
25 °C

Compressibility factor Z	9.7509E-1
Cp/Cv ratio γ	1.2966
Gas density (at boiling point)	3.057 kg/m³
Gas density	2.9305 kg/m³
Gas/(liquid at boiling point) equivalent	498.58 vol/vol
Heat capacity Cp	6.6921E-1 kJ/(kg.K)
Heat capacity Cv	5.1614E-1 kJ/(kg.K)
Specific gravity	2.26
Specific volume	3.412E-1 m³/kg
Thermal conductivity	8.434 mW/(m.K)
Vapor pressure	1.5637 bar
Viscosity	1.1796E-4 Po

Compressibility factor Z	9.8025E-1
Cp/Cv ratio γ	1.2863
Gas density	2.7633 kg/m³
Gas/(liquid at boiling point) equivalent	528.75 vol/vol
Heat capacity Cp	6.5898E-1 kJ/(kg.K)
Heat capacity Cv	5.123E-1 kJ/(kg.K)
Solubility in water	3.45E-2 mol/mol
Specific gravity	2.26
Specific volume	3.619E-1 m³/kg
Thermal conductivity	9.092 mW/(m.K)
Vapor pressure	2.8104 bar
Viscosity	1.2475E-4 Po

Compressibility factor Z	9.8285E-1
Cp/Cv ratio γ	1.2805
Gas density	2.6636 kg/m³
Gas/(liquid at boiling point) equivalent	548.54 vol/vol
Heat capacity Cp	6.562E-1 kJ/(kg.K)
Heat capacity Cv	5.1246E-1 kJ/(kg.K)
Solubility in water	2.46E-2 mol/mol
Specific gravity	2.26
Specific volume	3.754E-1 m³/kg
Thermal conductivity	9.54 mW/(m.K)
Vapor pressure	4.0015 bar
Viscosity	1.2924E-4 Po

Applications

Examples of uses of this molecule in Industry and Healthcare

Beverage

Sulfur dioxide allows to preserve wines from microbes or further oxidation during winemaking.

Electronic components

Sulfur dioxide is used as an additive to etching gas mixtures.

Food

Sulfur dioxide is used to preserve, fumigate and bleach grain.

Laboratories & Research Centers

Sulfur dioxide is used in calibration gas mixtures for petrochemical industry, environmental emission monitoring, industrial hygiene monitors and trace impurity analyzers.

Other

Sulfur dioxide is used as a flotation depressant for sulfide ores in the mining industry.

Pulp & Paper

Sulfur dioxide is used to bleach paper pulp.

Safety & Compatibility

Major Hazards
Material Compatibility

GHS04

Gas under pressure

GHS05

Corrosive

GHS06

Acute Toxicity

Threshold of toxicity

ILV-15min EU (at Patm and 293.15 K)	2.7 mg/m³ or 1 ppm
ILV-8h EU (at Patm and 293.15 K)	1.3 mg/m³ or 0.5 ppm
PEL USA OSHA (vol)	5 ppm
VLEP 8h France (at Patm and 293.15 K)	1.3 mg/m³ or 0.5 ppm
VLEP CT France (at Patm and 293.15 K)	2.7 mg/m³ or 1 ppm

Odor

Pungent and irritating

Metals

Aluminium	Satisfactory
Brass	Risk of stress corrosion cracking in long-term wet conditions Acceptable
Monel	Satisfactory
Copper	No data
Ferritic Steel	Sulfur dioxide hydrolyzes in presence of free water to produce sulfurous acid which is highly corrosive to steel Acceptable
Stainless steel	Sulfur dioxide hydrolyzes in presence of free water to produce sulfurous acid which is highly corrosive to steel Acceptable
Zinc	No data
Titanium	No data

Plastics

Polytetrafluoroethylene	Satisfactory
Polychlorotrifluoroethylene	Satisfactory
Polyvinylidene fluoride	Satisfactory
Polyvinyl chloride	Significant loss of mass Not recommended
Ethylene tetrafluoroethylene	No data
Polycarbonate	No data
Polyamide	significant loss of mass Not recommended
Polypropylene	Satisfactory

Elastomers

Butyl (isobutene- isoprene) rubber	Satisfactory
Nitrile rubber	Significant loss of mass Not recommended
Chloroprene	Significant loss of mass Not recommended
Chlorofluorocarbons	No data
Silicone	Significant loss of mass Not recommended
Perfluoroelastomers	Significant loss of mass Not recommended
Fluoroelastomers	Significant loss of mass Not recommended
Neoprene	No data
Polyurethane	Satisfactory
Ethylene-Propylene	Satisfactory

Lubricants

Hydrocarbon based lubricant	Significant loss of mass and material contamination Not recommended
Fluorocarbon based lubricant	material contamination Not recommended

Materials compatibility

Recommendations : Air Liquide has gathered data on the compatibility of gases with materials to assist you in evaluating which materials to use for a gas system. Although the information has been compiled from what Air Liquide believes are reliable sources (International Standards: Compatibility of cylinder and valve materials with gas content; Part 1- Metallic materials: ISO11114-1 (March 2012), Part 2 - Non-metallic materials: ISO11114-2 (April 2013), it must be used with extreme caution and engineering judgement. No raw data such as these can cover all conditions of concentration, temperature, humidity, impurities and aeration. It is therefore recommended that this table is only used to identify possible materials for applications at high pressure and ambient temperature. Extensive investigation and testing under the specific conditions of use need to be carried out to validate a material selection for a given application. Contact the regional Air Liquide team for expertise service.

Learn More

More information

Sulfur dioxide is a noticeable component in the atmosphere, especially following volcanic eruptions.