Dimethyl Sulfoxide

1Identification

Name

Dimethyl Sulfoxide

IUPAC name

methylsulfinylmethane

CAS number

67-68-5

EC number

200-664-3

Molecular formula

C2H6OS

Molecular weight

78.14 g/mol

InChIKey

IAZDPXIOMUYVGZ-UHFFFAOYSA-N

SMILES

CS(=O)C

PubChem CID

679

Synonyms

dimethyl sulfoxide, DMSO, Methylsulfinylmethane, Methyl sulfoxide, Dimethyl sulphoxide, Dimethylsulfoxide, sulfinylbismethane, Demasorb, Domoso, Methane, sulfinylbis-, Demsodrox, Dromisol, Deltan, Demavet

Recommended uses

• Used as a pharmaceutical, a solvent for polymerization and chemical extractions, a paint remover, a preservative for organ transplantation; Occurs naturally in ground water and in grains, vegetables, and many other foods; [CHEMINFO] Used as a solvent for many organic compounds; Also used in industrial cleaners; [HSDB]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Semiconductor Manufacturing [Category: Industry]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• DMSO is not a nutritional supplement. It is used as a treatment for interstitial cystitis, and treatment must be performed by a qualified physician. DMSO is metabolized to methylsulfonylmethane, which is available as a nutritional supplement.
  Hazardous Substances Data Bank (HSDB)
• Laboratory chemicals Etching agent Not Known or Reasonably Ascertainable Cleaning agent Plating agent Solvent
  EPA Chemical Data Reporting (CDR)
• Solvent Cleaning agent Not Known or Reasonably Ascertainable Soil amendments (fertilizers)
  EPA Chemical Data Reporting (CDR)

Use categories: Animal Drugs -> FDA Approved Animal Drug Products (Green Book) -> Active Ingredients · Fragrance Ingredients · Flavouring Agent -> FLAVOURING_AGENT -> JECFA Functional Classes · Flavoring Agents -> JECFA Flavorings Index

Description

• 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.
  CAMEO Chemicals
• Dimethyl sulfoxide is a 2-carbon sulfoxide in which the sulfur atom has two methyl substituents. It has a role as a geroprotector, an alkylating agent, a non-narcotic analgesic, a MRI contrast agent, a polar aprotic solvent, a radical scavenger, an antidote and an Escherichia coli metabolite. It is a volatile organic compound and a sulfoxide.
  ChEBI
• A highly polar organic liquid, that is used widely as a chemical solvent. Because of its ability to penetrate biological membranes, it is used as a vehicle for topical application of pharmaceuticals. It is also used to protect tissue during cryopreservation. Dimethyl sulfoxide shows a range of pharmacological activity including analgesia and anti-inflammation.
  DrugBank

2Hazard identification

Signal word

Warning

Pictograms

GHS07

Classification source

European Chemicals Agency (ECHA)

Precautionary statements

Other reported classifications

3 classification records exist across sources. Differences usually reflect purity, physical form or impurities.

NFPA 704 rating

• 2 - Materials that, under emergency conditions, can cause temporary incapacitation or residual injury.
  Hazardous Substances Data Bank (HSDB)
• 2 - Materials that must be moderately heated or exposed to relatively high ambient temperatures before ignition can occur. Materials would not under normal conditions form hazardous atmospheres with air, but under high ambient temperatures or under moderate heating could release vapor in sufficient quantities to produce hazardous atmospheres with air.
  Hazardous Substances Data Bank (HSDB)
• 0 - Materials that in themselves are normally stable, even under fire conditions.
  Hazardous Substances Data Bank (HSDB)

Health hazards

• Slight eye irritation. (USCG, 1999)
  CAMEO Chemicals

Fire hazards

• Special Hazards of Combustion Products: Sulfur dioxide, formaldehyde, and methyl mercaptan can form (USCG, 1999)
  CAMEO Chemicals
• Combustible. Gives off irritating or toxic fumes (or gases) in a fire. Above 87 °C explosive vapour/air mixtures may be formed. Risk of fire and explosion on contact with incompatible substances. See Chemical Dangers.
  ILO-WHO International Chemical Safety Cards (ICSCs)

Hazards summary

• A skin and eye irritant; May cause CNS depression after inhalation, ingestion, or skin absorption of high doses; Long term use may cause adverse effects to the liver and blood; [ICSC] Rats experienced no significant effects after inhalation of 200 mg/m3 (62.8 ppm) for 30 days. After skin absorption, humans may experience garlic odor on the breath, headache, nausea, and dizziness. DMSO enhances the absorption of other drugs. [CHEMINFO] Health effects after inhalation of high concentrations may include headache, dizziness, and sedation. [CAMEO] Dermal doses as high as 1 g/kg per day have been shown to have no significant adverse clinical effects in well-controlled human studies. [AIHA]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

3Composition / information on ingredients

This page describes the pure substance. Commercial products may be solutions or mixtures. Check Section 3 of your supplier's SDS for concentrations and other ingredients.

4First-aid measures

• 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. Gently wash all affected skin areas thoroughly with soap and water.
  CAMEO Chemicals

Symptoms of exposure

• Garlic odour. Headache. Nausea.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Redness.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Garlic breath. Nausea. Vomiting. Drowsiness. Diarrhoea.
  ILO-WHO International Chemical Safety Cards (ICSCs)

5Fire-fighting measures

• For small (incipient) fires, use media such as "alcohol" foam, dry chemical, or carbon dioxide. For large fires, apply water from as far as possible. Use very large quantities (flooding) of water applied as a mist or spray; solid streams of water may be ineffective. Cool all affected containers with flooding quantities of water.
  Hazardous Substances Data Bank (HSDB)
• Wear self contained breathing apparatus for fire fighting if necessary.
  Hazardous Substances Data Bank (HSDB)
• To fight fire use water, foam, alcohol foam, carbon dioxide, dry chemical.
  Hazardous Substances Data Bank (HSDB)

Hazardous combustion products

• Special hazards arising from the substance or mixture: Carbon oxides, Sulphur oxides
  Hazardous Substances Data Bank (HSDB)

6Accidental release measures

Isolation and evacuation

• Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary. FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)
  CAMEO Chemicals

Spill cleanup

• Remove all ignition sources. Personal protection: protective gloves, protective clothing, safety goggles and filter respirator for organic gases and vapours adapted to the airborne concentration of the substance. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Accidental Release Measures. Personal precaustions, protective equipment and emergency procedure: Avoid breathing vapors, mist or gas. Remove all sources of ignition. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areas.; Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let products enter drains.; Methods and materials for containment adn cleaning up: Contain spillage, and then collect with an electrically protected vacuum cleaner or by wet-brushing and place in container for disposal according to local regulations. Keep in suitable, closed containers for disposal.
  Hazardous Substances Data Bank (HSDB)

7Handling and storage

• Separated from incompatible materials and : see Chemical Dangers. Well closed. Cool. Dry. Keep in the dark. Keep in a well-ventilated room.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Store away from oxidizing agents, heat, and ignition sources.
  Hazardous Substances Data Bank (HSDB)

8Exposure controls / personal protection

No occupational exposure limits found in our sources.

Personal protective equipment

• Butyl rubber gloves, safety goggles. Respiratory filter if airborne sprays or drops are present. (USCG, 1999)
  CAMEO Chemicals
• Chemical-resistant gloves, Protective eyewear.
  Hazardous Substances Data Bank (HSDB)

9Physical and chemical properties

10Stability and reactivity

Reactivity

• DIMETHYL SULFOXIDE decomposes violently on contact with many acyl halides and related compounds such as acetyl chloride, benzenesulfonyl chloride, benzoyl chloride, cyanuric chloride, phosphorus trichloride, phosphorus oxychloride, and thionyl chloride [Chem. Eng. News 35(9):87 (1957)].
  CAMEO Chemicals
• Denser than water and miscible in water.
  CAMEO Chemicals

Incompatible materials and hazardous reactions

• ... can react with oxidizing materials.
  Hazardous Substances Data Bank (HSDB)
• 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).
  Hazardous Substances Data Bank (HSDB)
• 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.
  Hazardous Substances Data Bank (HSDB)

11Toxicological information

Short-term exposure effects

• The substance is mildly irritating to the eyes and skin. Exposure to high concentrations could cause lowering of consciousness. May accelerate skin absorption of other materials.
  ILO-WHO International Chemical Safety Cards (ICSCs)

Long-term exposure effects

• The substance defats the skin, which may cause dryness or cracking.
  ILO-WHO International Chemical Safety Cards (ICSCs)

12Ecological information

Not available in the public sources we compile. Check Section 12 of the supplier's SDS.

13Disposal considerations

• SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.
  Hazardous Substances Data Bank (HSDB)
• This combustible material may be burned in a chemical incinerator equipped with an afterburner and scrubber. Offer surplus and non-recyclable solutions to a licensed disposal company.
  Hazardous Substances Data Bank (HSDB)

14Transport information

DOT label

• Poison
  CAMEO Chemicals

Not available in the public sources we compile. Check Section 14 of the supplier's SDS.

How DOT hazard classes work →

15Regulatory information

• This action promulgates standards of performance for equipment leaks of Volatile Organic Compounds (VOC) in the Synthetic Organic Chemical Manufacturing Industry (SOCMI). The intended effect of these standards is to require all newly constructed, modified, and reconstructed SOCMI process units to use the best demonstrated system of continuous emission reduction for equipment leaks of VOC, considering costs, non air quality health and environmental impact and energy requirements. Dimethyl sulfoxide is produced, as an intermediate or a final product, by process units covered under this subpart.
  Hazardous Substances Data Bank (HSDB)
• Residues of dimethyl sulfoxide are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops only. Use: solvent or cosolvent for formulations used before crop emerges from soil or prior to formation of edible parts of food plants.
  Hazardous Substances Data Bank (HSDB)
• Dimethyl sulfoxide (DMSO) ... is exempted from the requirement of a tolerance when used as an inert solvent or cosolvent in formulations with the following pesticides when used in accordance with good agricultural practices in or on the following raw agricultural commodities: (a) Carbaryl (1-naphthyl methyl-carbamate) - pea, dry, seed; pea, succulent (b) O-O-Diethyl O-(2-isopropyl-6-methyl-4-pyrimidinyl) phosphorothioate - pea, dry, seed; pea, succulent.
  Hazardous Substances Data Bank (HSDB)
• The Approved Drug Products with Therapeutic Equivalence Evaluations identifies currently marketed prescription drug products, including dimethyl sulfoxide, approved on the basis of safety and effectiveness by FDA under sections 505 of the Federal Food, Drug, and Cosmetic Act.
  Hazardous Substances Data Bank (HSDB)

Overview of SDS regulations (OSHA HazCom, WHMIS, REACH/CLP) →

16Other information

Compiled from PubChem CID 679 and the sources it aggregates (attributed inline). Data retrieved 2026-10-12. This summary describes the pure substance and is not a supplier SDS.