Dimethyl Sulfoxide (DMSO) (CH3)2SO

What is DMSO - Dimethyl Sulfoxide?

DMSO (Dimethyl Sulfoxide) is an organosulfur compound with the formula (CH₃)₂SO. It is a colorless liquid and is a powerful solvent. It dissolves both polar and non-polar compounds. This property makes the DMSO miscible in a wide range of organic solvents as well as water.

Sigma Aldrich Dimethyl Sulfoxide Lewis Structure

DMSO is a potent solvent because of its highly polar nature. DMSO works with ionic compounds, certain salts, and non-ionic compounds. There are some limitations to its use when used with non-polar compounds.

Use DMSO when your application calls for a polar, aprotic solvent that's easily able to dissolve many substances that have extremely poor solubility in water.

As a leading supplier of high-purity solvents, we offer the right product for your application no matter which dimethyl sulfoxide compound or grade (including ASC and HPLC) you need.  


DMSO Formulas and Structures

Dimethyl Sulfoxide, DMSO, has a a central sulfur atom that is bound to two methyl groups through single bonds and an oxygen atom joined through a double bond to the sulfur atom.

Type Formula or Structure
Dimethyl Sulfoxide Molecular Formulas C2H6OS, CH3-SO-CH3, CH3SOCH3, (CH3)2SO
Dimethyl Sulfoxide Ball and Sticks Structural Model Sigma Aldrich Dimethyl Sulfoxide Ball-Stick Model
Dimethyl Sulfoxide Sticks Structural Model Sigma Aldrich Dimethyl Sulfoxide Stick Model
Dimethyl Sulfoxide Wire-Frame Structural Model Sigma Aldrich Dimethyl Sulfoxide Wire-Frame Model
Dimethyl Sulfoxide Spce-Filling Structural Model Sigma Aldrich Dimethyl Sulfoxide Space-Filling Model

DMSO - Dimethyl Sulfoxide Industrial Identification

Chart listing the various names, identifiers and synonyms of dimethyl sulfoxide.

ID Type Identification
Synonyms Dimethyl Sulphoxide, Methylsulfinylmethane, Methanesulfinylmethane, Methyl sulfoxide, Dimethyl(oxido)sulfur
Beilstein Registry 506008
EG/EC Number 2006643
MDL Number MFCD00002089
CAS Number 67-68-5
RIDADR / UN Number NA 1993 / PGIII
NSC Number 760436 
ICSC Number 0459
RTECS Number 85232



DMSO Physical and Chemical Properties

Chart including the physical and chemical properties of DMSO. (Sources: Merck Index, Pubchem)

Property Value
Molecular Weight (mw) 78.13
Density 1.100 g/mL at 25 ºC
Boiling Point/Freezing Point
189 ºC
Melting Point 16-19 ºC
Flash Point 85.0 °C
Viscosity (cP)  1.987 at 25 °C
Dielectric Constant 47.24 at 20 ºC
Dipole Moment 3.960
UV cutoff 265 nm
Refractive Index 1.479 at 20 ºC
Vapor Density 2.7 (vs. air)
Vapor Pressure 0.42 mmHg at 20 ° C
Water Solubility 12.80 M
Heat of Combustion -10,890 Btu/lb = -6050 Cal/g
Heat of Vaporization 47.3 kJ/mol at 70 ºC
Dissociation Constants pKa = 35.1

DMSO Miscibility and Immiscibility

Property Chemical
Miscible with Acetic Acid, Acetone, Acetonitrile, Benzene, Butanol, Methyl ethyl ketone (MEK), Butyl Acetate (n-), Methyl tert-butyl ether (MTBE), Carbon Tetrachloride, Chloroform, Dichloroethane (1, 2), Dichloromethane, Diisopropyl ether, Dimethylformamide, Dimethyl Sulfoxide (DMSO), Dioxane, Ethanol, Ethyl Acetate, Methanol, 1-Propanol, Isopropanol, Tetrahydrofuran (THF), Toluene, Trichloroethylene, Water
Immiscible with Cyclohexane, Diethyl ether, Heptane, Hexane, Pentane, Isooctane, Xylene
Miscibility Information and Solvent Miscibility Table




Download Dimethyl Sulfoxide Miscibility Table

DMSO Compatability

The compatability of DMSO with various materials is listed in the table below.

Compatability With Materials
Compatible LDPE, HDPE, polypropylene, PPCO (polypropylene copolymer), polymethylpentene, nylon, teflon FEP
Moderately compatible polystyrene, ECTFE/ETFE
Incompatible polysulfone, flexible and rigid PVC tubing, polycarbonate



DMSO Hazard Statements

Hazard Statements H227
Signal Word Warning
Precautionary Statements P210-P280-P370 + P378-P403 + P235-P501


GHS Information

GHS Pictogram Statement
Flammable liquids, category 4


DMSO SDS Information

An SDS (Safety Data Sheet) is available for each DMSO product. Start your search for an SDS.


What is DMSO Used For?

DMSO is used as:

  • Reagent in organic synthesis. 
  • Industrial solvent.
  • Antifreeze or hydraulic fluid when mixed with water. 
  • Cryopreserve and store cultured cells.

Some examples of these common uses are:

As a solvent in the Pfitzner-Moffatt oxidation reaction, moderate oxidation of primary and secondary alcohols are promoted by dicyclohexylcarbodiimide activation of dimethyl sulfoxide.


Sigma Aldrich Dimethyl Sulfoxide Pfitzner Moffat Oxidation


In the Swern oxidation reaction, moderate oxidation of primary and secondary alcohols is promoted by oxalyl chloride activation of dimethyl sulfoxide. Evidently involving the dimethyl alkoxysulfonium salts.  


Sigma Aldrich Dimethyl Sulfoxide Swern Oxidation


DMSO Precautions and Disclaimer

This product is for R&D use only, not for drug, household, or other uses. Please, consult the Safety Data Sheet for hazards information and safe handling practices.

DMSO Preparation Instructions

This product is miscible in water (1 ml DMSO + 1 ml H2O), yielding a clear, colorless solution. DMSO is a very hygroscopic liquid; should be protected from exposure to moisture.

DMSO is also soluble in ethanol, acetone, ether, benzene, and chloroform. More miscibility information is provided above and via the Miscibility/Immiscibility Table.


DMSO Storage/Stability

Store at room temperature.

The product may arrive as a solid instead of a liquid. But, it can be liquified warming to room temperature without detriment the product

DMSO is stable up to 100 °C in alkaline, acidic, and neutral conditions. Also, it is stable in the same conditions up to temperatures close to its boiling point,

DMSO is thermally stable. It can be heated to 150 °C for 24 hours with less than 0.1% loss in purity.12

To prepare a sterile filtered DMSO solution is recommended to use a Teflon (PTFE) or nylon membrane. It is not recommended to use Cellulose acetate membranes.

DMSO Specificity

D8418 is designated as Molecular Biology grade and is suitable for molecular biology applications. It has been analyzed for the presence of nucleases and proteases.

D2650 is a Hybri-MaxTM product. It is hybridoma tested and is assessed for suitability in cell freezing. It is sterile filtered and tested for endotoxin levels.

Find other specification information on individual product pages.

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