Dimethyl sulfoxide

Athanor · official

C₂H₆OS · 78.14 g/mol

IUPAC name: methylsulfinylmethane

Also called DMSO, methyl sulfoxide

Solvents Functional groups

Open in Athanor

Drawn from its SMILES with RDKit

WarningCauses skin irritation · Causes serious eye irritation · May cause respiratory irritation

Names and identifiers

IUPAC name: methylsulfinylmethane
Synonyms: DMSO, methyl sulfoxide, Methylsulfinylmethane
+ 36 more
Methyl sulfoxide, Dimethyl sulphoxide, Dimethylsulfoxide, sulfinylbismethane, Demasorb, Domoso, Methane, sulfinylbis-, Demsodrox, Dromisol, Deltan, Demavet, Demeso, Dolicur, Hyadur, Infiltrina, Somipront, Dimexide, Durasorb, Syntexan, Dermasorb, Dimethyl sulfur oxide, Doligur, Dipirartril-tropico, Gamasol 90, Herpid, Topsym, Dimethylsulfoxyde, Sulfinylbis(methane), Rimso-50, Dimethylsulfoxid, Dimetil sulfoxido, Dimethylsulphoxide, (methylsulfinyl)methane, SQ 9453, NSC-763, Rimso 50
Molecular formula: C₂H₆OS
Empirical formula: C₂H₆OS
Molecular weight: 78.14 g/mol
Exact mass: 78.01394
CAS number: 67-68-5
PubChem CID: 679
Canonical SMILES: CS(=O)C
Isomeric SMILES: CS(=O)C
InChI: InChI=1S/C2H6OS/c1-4(2)3/h1-2H3
InChIKey: IAZDPXIOMUYVGZ-UHFFFAOYSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Physical properties

TemperaturePressureDensity

Appearance: Colorless liquid[4]
4 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– Dimethyl sulfoxide appears as a clear liquid, essentially odorless. Closed cup flash point 192 °F. Vapors are heavier than air. Contact with the skin may cause stinging and burning and lead to an odor of garlic on the breath. An excellent solvent that can transport toxic solutes through the skin. High vapor concentrations may cause headache, dizziness, and sedation. [1] CAMEO Chemicals
– Liquid [2] EPA Chemical Data Reporting (CDR)
– COLOURLESS HYGROSCOPIC LIQUID. [3] ILO-WHO International Chemical Safety Cards (ICSCs)
–shown Colorless liquid [4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 454
Odor: Slightly sulfurous odor[4]
2 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
–shown Slightly sulfurous odor [4] Hazardous Substances Data Bank (HSDB)cites Lefaux, R. Practical Toxicology of Plastics. Cleveland: CRC Press Inc., 1968., p. 120
– Distinctive garlic or oyster-like odor [4] Hazardous Substances Data Bank (HSDB)cites Arena, J.M. and Drew, R.H. (eds.) Poisoning-Toxicology, Symptoms, Treatments. 5th ed. Springfield, IL: Charles C. Thomas Publisher, 1986., p. 824
Melting point: 17.89 °C[5]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source
18.5 °C 65.3 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
18.5 °C 18.5 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
17.9 °Cshown 17.89 °C [5] PAC Chemical Database, U.S. Department of Energy
Boiling point: 189 °C[3]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source
189 °C 372 °F at 760 mmHg (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
189 °Cshown 189 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
189 °C 189 °C @760 [mm Hg] [5] PAC Chemical Database, U.S. Department of Energy
Density: 1.101 @25 °C[5]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source
– 1.101 at 68 °F (USCG, 1999) - Denser than water [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
– Relative density (water = 1): 1.1 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
–shown 1.101 @25 °C [5] PAC Chemical Database, U.S. Department of Energy
Solubility in water: Solubility in water: miscible[3]
4 values
From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.
Value As written Source
– greater than or equal to 100 mg/mL at 68 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
– Miscible with water [4] Hazardous Substances Data Bank (HSDB)cites Dorigan J et al; Preliminary scoring of selected organic air pollutants. Appendix II-Chemistry, production, and toxicity of chemicals D through E. Research Triangle Park, NC: US EPA, USEPA-450/3-77-008C. pp.327 (1976)
– Soluble in chloroform and benzene [4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 454
–shown Solubility in water: miscible [3] ILO-WHO International Chemical Safety Cards (ICSCs)
log P: -1.35 (calculated)[3]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
– log Kow = -1.35 [4] Hazardous Substances Data Bank (HSDB)cites Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 5
–shown -1.35 (calculated) [3] ILO-WHO International Chemical Safety Cards (ICSCs)
pKa: pKa = 35.1[4]
Vapor pressure: Vapor pressure, Pa at 20 °C: 59.4[3]
4 values
Sources disagree; from ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative.
Value As written Source
0.42 mmHg 0.42 mmHg at 68 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
0.6 mmHg 0.60 mm Hg at 25 °C [4] Hazardous Substances Data Bank (HSDB)cites Daubert TE, Danner RP; Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, DC: Taylor and Francis (2002)
0.45 mmHgshown Vapor pressure, Pa at 20 °C: 59.4 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
0.75 mmHg 0.75 [mm Hg] @27.4 °C [5] PAC Chemical Database, U.S. Department of Energy
1 more value was reported but failed the checks (unreadable or out of range), so it is not shown.
Flash point: 95 °C (203 °F, NTP 1992)[1]
3 values
2 of 3 sources agree on it (most common value).
Value As written Source
95 °Cshown 203 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
95 °C 95 °C (203 °F) (Open cup) [4] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-52
87 °C 87 °C c.c. [3] ILO-WHO International Chemical Safety Cards (ICSCs)
Autoignition temperature: 215 °C[3]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source
215 °C 419 °F (USCG, 1999) [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
215 °C 419 °F (215 °C) [4] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-52
215 °Cshown 215 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
Viscosity: Reported, but no value passed the checks.
The value and why
1.95 mm²/s at 20 °C (could not be read; source [3])
Refractive index: Reported, but no value passed the checks.
The value and why
Index refraction: 1.4770 at 20 °C/D (could not be read; source [4])

Value	As written	Source
–	Dimethyl sulfoxide appears as a clear liquid, essentially odorless. Closed cup flash point 192 °F. Vapors are heavier than air. Contact with the skin may cause stinging and burning and lead to an odor of garlic on the breath. An excellent solvent that can transport toxic solutes through the skin. High vapor concentrations may cause headache, dizziness, and sedation.	[1] CAMEO Chemicals
–	Liquid	[2] EPA Chemical Data Reporting (CDR)
–	COLOURLESS HYGROSCOPIC LIQUID.	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–shown	Colorless liquid	[4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 454

Value	As written	Source
–shown	Slightly sulfurous odor	[4] Hazardous Substances Data Bank (HSDB)cites Lefaux, R. Practical Toxicology of Plastics. Cleveland: CRC Press Inc., 1968., p. 120
–	Distinctive garlic or oyster-like odor	[4] Hazardous Substances Data Bank (HSDB)cites Arena, J.M. and Drew, R.H. (eds.) Poisoning-Toxicology, Symptoms, Treatments. 5th ed. Springfield, IL: Charles C. Thomas Publisher, 1986., p. 824

Value	As written	Source
18.5 °C	65.3 °F (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
18.5 °C	18.5 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
17.9 °Cshown	17.89 °C	[5] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
189 °C	372 °F at 760 mmHg (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
189 °Cshown	189 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
189 °C	189 °C @760 [mm Hg]	[5] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
–	1.101 at 68 °F (USCG, 1999) - Denser than water	[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
–	Relative density (water = 1): 1.1	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–shown	1.101 @25 °C	[5] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
–	greater than or equal to 100 mg/mL at 68 °F (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
–	Miscible with water	[4] Hazardous Substances Data Bank (HSDB)cites Dorigan J et al; Preliminary scoring of selected organic air pollutants. Appendix II-Chemistry, production, and toxicity of chemicals D through E. Research Triangle Park, NC: US EPA, USEPA-450/3-77-008C. pp.327 (1976)
–	Soluble in chloroform and benzene	[4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 454
–shown	Solubility in water: miscible	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–	log Kow = -1.35	[4] Hazardous Substances Data Bank (HSDB)cites Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 5
–shown	-1.35 (calculated)	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
0.42 mmHg	0.42 mmHg at 68 °F (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
0.6 mmHg	0.60 mm Hg at 25 °C	[4] Hazardous Substances Data Bank (HSDB)cites Daubert TE, Danner RP; Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, DC: Taylor and Francis (2002)
0.45 mmHgshown	Vapor pressure, Pa at 20 °C: 59.4	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
0.75 mmHg	0.75 [mm Hg] @27.4 °C	[5] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
95 °Cshown	203 °F (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
95 °C	95 °C (203 °F) (Open cup)	[4] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-52
87 °C	87 °C c.c.	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
215 °C	419 °F (USCG, 1999)	[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
215 °C	419 °F (215 °C)	[4] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-52
215 °Cshown	215 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Each value as its source reports it, with the source's number after it (listed under References). Where several sources report a property, the row shows the value most of them agree on, the rule the app uses; open the values to see every one.

Calculated

Heavy atoms: 4
Rings: 0
Aromatic rings: 0
Fraction sp³ carbons (Fsp3): 1
H-bond donors: 0
H-bond acceptors: 1 computed here · PubChem 2
Rotatable bonds: 0
TPSA (Å²): 17.1 computed here · PubChem 36.3
Formal charge: 0
XLogP3: -0.6 PubChem
Complexity: 29 PubChem
Stereocenters: None
Double-bond geometry: None specified
Point group: Cs of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

C30.74%
H7.74%
O20.48%
S41.04%

Isotope pattern

Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.

Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.

Predicted

log P: -0.01 Crippen (Wildman and Crippen 1999)
log S (water solubility): -0.32 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 3.11 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 78.14
log P ≤ 5 (Crippen): -0.01
H-bond donors ≤ 5: 0
H-bond acceptors ≤ 10: 1

Passes all four rules.

¹³C NMR shifts, predicted

Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.

Safety

Warning

Most widely reported: 938 company reports to ECHA. Source [6].

Harmful or irritant

NFPA 704[4]

H315Causes skin irritation (28.4% of reports)
H319Causes serious eye irritation (33.6% of reports)
H335May cause respiratory irritation (13.8% of reports)

Precautionary statements: P261, P264, P264+P265, P271, P280, P302+P352, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, P501

View all classifications (3)

[6] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 65.1% (611 of 938) of all reports.
[6] European Chemicals Agency (ECHA) · 938 reports · WarningH315, H319, H335
[4] Hazardous Substances Data Bank (HSDB) · WarningH227

Exposure limits

MAK (Maximale Arbeitsplatz Konzentration): 160 mg/m[3]

First aid

Eyes: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. Immediately transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop. Skin: Immediately flood affected skin with water while removing and isolating all contaminated clothing.[1]
Fresh air, rest.[3]
Rinse with plenty of water for several minutes (remove contact lenses if easily possible).[3]
Rinse mouth. Refer for medical attention .[3]

Storage

Separated from incompatible materials and : See Chemical Dangers. Well closed. Cool. Dry. Keep in the dark. Keep in a well-ventilated room.[3]
Store away from oxidizing agents, heat, and ignition sources.[4]

Incompatibilities

... Can react with oxidizing materials.[4]
Violent or explosive reaction with many acyl, aryl, and nonmetal halides (e.g., acetyl chloride, benzenesulfonyl chloride, bromobenzoyl actanilide, cyanuric chloride, iodine pentafluoride, Mg(ClO4)2, CH3Br, NiO4, oxalyl chloride, P2O3, phosphorus trichloride, phosphoryl chloride, silver fluoride, silver difluoride, sodium hydride, sulfur dichloride, disulfur dichloride, sulfurylchloride, tetrachlorosilane, and thionyl chloride).[4]
Violent or explosive reaction with boron compounds (eg borane, nonahydrononaborate (2-) ion), 4(4'-bromobenzoyl)acetanilide, carbonyl diisothiocyanate, dinitrogen tetraoxide, hexachlorocyclotriphosphazine, copper + trichloroacetic acid, metal alkoxides (eg potassium tert-butoxide, sodium isopropoxide), trifluoroacetic acid anhydride.[4]
Incompatible with magnesium perchlorate, metal oxosalts, perchloric acid, periodic acid, sulfur trioxide.[4]

Safety data sheets on the supplier’s page: VladaChem, J&H Chemical Co.,ltd, Alfa Chemistry.

Always read the supplier’s safety data sheet before working with it.

Spectra

Experimental spectra held by these sources; each link opens the source's own record.

Literature

Reading PubChem, OpenAlex and GSRS…

Bioactivity

Reading ChEMBL…

References

[1]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
[2]EPA Chemical Data Reporting (CDR) · Public domain (US EPA) · via PubChem · retrieved 2026-10-14
[3]ILO-WHO International Chemical Safety Cards (ICSCs) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[4]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[5]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
[6]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[7]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
[8]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
[9]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[10]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[11]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
[12]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
·Literature on PubChem

Data last updated 2026-10-14.