DMSO DIMETHYL SULFOXIDE

DMSO Dimethyl Sulfoxide, also known as methyl sulfoxide or methylsulfinylmethane, is an organosulfur solvent with CAS 67-68-5 and formula C2H6OS, used in chemical synthesis, polymer processing, cleaning and research. Its strong polarity, complete water miscibility and low volatility make it useful for dissolving selected organic compounds, salts and polymers. The sulfoxide group supports ion solvation and hydrogen-bond acceptance, while its interactions with water and biological membranes also underpin specialized cryopreservation applications.

CAS No: 67-68-5
EC No: 200-664-3
Molecular formula: C2H6OS
Molecular weight: 78.13 g/mol
Appearance: Clear, colorless liquid above its freezing point
Freezing point: Approximately 18.5 °C
Boiling point: Approximately 189 °C at atmospheric pressure
Density: Approximately 1.10 g/cm³ at 20 °C
Water solubility: Miscible in all proportions
Flash point: Approximately 87 °C, closed cup

WHAT IS DMSO DIMETHYL SULFOXIDE?

DMSO Dimethyl Sulfoxide is a polar aprotic sulfoxide solvent used in pharmaceutical and agrochemical synthesis, polymer solutions, coating removal, electronics processing and biological research. Methyl sulfoxide, CAS 67-68-5, can combine broad solvent power with relatively slow evaporation, but it is not a universal solvent for every material.

In a reaction mixture, the solvent can improve contact between compatible organic substrates and ionic reagents. For a cleaning formulator, its ability to penetrate and swell selected polymer films is often more important than reaction chemistry. Successful dissolution, stripping and extraction must each be demonstrated for the actual material.

Industrial production uses controlled oxidation of dimethyl sulfide followed by purification and distillation. Further purification and controlled packaging distinguish products intended for sensitive analytical, pharmaceutical or electronics work. The manufacturing route and specifications offered should be confirmed rather than inferred from the chemical name.

Commercial materials differ in water, assay, acidity, color, sulfur-containing impurities, metals and particles. Pharmacopoeial conformity does not by itself establish sterility, low endotoxin content or suitability for direct administration. A solvent suitable for general synthesis may fail a sensitive cell assay or semiconductor process.

Dimethyl sulfone, dimethyl sulfide and deuterated DMSO are separate substances. Ordinary dimethyl sulfoxide is also chemically different from the amide solvents DMF, DMAc and NMP, even when evaluated for a similar purpose.

COMMON PRODUCT & CHEMICAL NAMES OF DMSO DIMETHYL SULFOXIDE:

Dimethyl sulfoxide
Dimethyl sulphoxide
Dimethylsulfoxide
DMSO
Methyl sulfoxide
Methyl sulphoxide
Methylsulfinylmethane
Sulfinylbismethane
Me2SO
Dimethyl sulfoxide USP
Dimethyl sulfoxide Ph. Eur.
Anhydrous DMSO
Electronic grade DMSO
Cell culture grade DMSO

Sulfoxide and sulphoxide are spelling variants. DMSO and Me2SO are abbreviations, while methylsulfinylmethane is another chemical name for the same molecule. The final entries describe commercial qualities or intended uses, not different CAS identities or automatic approval for a finished application.

DMSO-d6 is a deuterated analytical solvent with CAS 2206-27-1. MSM means dimethyl sulfone, CAS 67-71-0, and must not be substituted for the liquid solvent in an order. Dimethyl sulfide, CAS 75-18-3, is the reduced sulfur compound used as a manufacturing precursor.

CAS NO, EC / EINECS NO AND CHEMICAL IDENTIFICATION OF DMSO DIMETHYL SULFOXIDE

Product name: DMSO Dimethyl Sulfoxide
Common abbreviation: DMSO
Chemical name: Dimethyl sulfoxide
Alternative chemical name: Methylsulfinylmethane
CAS No: 67-68-5
EC / EINECS No: 200-664-3
Molecular formula: C2H6OS
Molecular weight: 78.13 g/mol
Chemical class: Organosulfur sulfoxide, polar aprotic solvent
Main functions: Process solvent, polymer solvent, film-swelling solvent and specialized laboratory cryoprotectant
ICH Q3C residual solvent category: Class 3

The identifiers establish chemical identity, not the water limit, particle count, biological compatibility or regulatory suitability of a batch. REACH registration information exists for this substance, but supply-chain coverage and identified uses must be confirmed for the actual supplier and market.

CHEMICAL STRUCTURE AND MOLECULAR PROPERTIES OF DMSO DIMETHYL SULFOXIDE

Two methyl groups are bonded to sulfur in the structure (CH3)2SO. The sulfoxide group is strongly polarized, and the sulfur-centered geometry is pyramidal. Oxygen can accept hydrogen bonds from water and other donors, while the molecule contains no O-H or N-H hydrogen-bond donor group.

This combination explains why methyl sulfoxide mixes with water while also dissolving many selected organic substances. Strong polarity does not imply that every salt, polymer or nonpolar oil will dissolve. Temperature, concentration and the counterion can change the result.

HOW DOES DMSO DIMETHYL SULFOXIDE WORK AT THE MOLECULAR LEVEL?

As a polar aprotic solvent, DMSO can solvate cations and change the relative reactivity of dissolved anionic reagents. Faster substitution is possible in suitable chemistry, but rates also depend on substrate, ion pairing, water and competing reactions. The solvent must not be assumed inert in every synthetic system.

Within a compatible coating, methylsulfinylmethane can penetrate and swell the film, helping separate it from the substrate. Co-solvents or amines may contribute additional effects. Effective removal does not establish freedom from corrosion, polymer damage or redeposition.

In cryopreservation, the solvent enters cells and alters the freezing behavior of aqueous systems, helping reduce ice-related injury under an appropriate protocol. Cell compatibility depends on exposure time, concentration and temperature. Cryoprotection is not equivalent to harmlessness toward living cells.

Main functions:

Solvation of selected organic compounds and ionic reagents
Control of reaction-medium polarity
Swelling and removal of selected polymer films
Preparation of compatible polymer solutions
Cryoprotection in validated cell-specific procedures

Water content, additives and thermal history can substantially change these functions. Activated sulfoxide oxidation chemistry and strongly basic reactions require dedicated reaction-safety assessment rather than treating DMSO as a passive carrier.

PHYSICAL AND CHEMICAL PROPERTIES OF DMSO DIMETHYL SULFOXIDE

General technical characteristics:

Physical appearance: Clear, colorless liquid, crystalline solid below approximately 18.5 °C
Chemical character: Polar aprotic, hygroscopic solvent
Molecular formula: C2H6OS
Molecular weight: 78.13 g/mol
Purity: A representative molecular-biology product specifies at least 99.9 %
Water content: A representative molecular-biology product specifies at most 0.1 %
Density: Approximately 1.10 g/cm³ at 20 °C
Dynamic viscosity: Approximately 2.14 mPa·s at 20 °C
Vapor pressure: Approximately 0.55 hPa at 20 °C
Freezing point: Approximately 18.5 °C
Boiling point: Approximately 189 °C at atmospheric pressure
Flash point: Approximately 87 °C, closed cup
Water compatibility: Completely miscible, with heat released during mixing

The purity and water limits above describe a published product example, not all industrial supply. An anhydrous designation requires its own numerical water specification. Karl Fischer analysis is useful for water control, while a separate assay and impurity profile establish composition more fully.

Freezing behavior matters for drum unloading and pipework. Water and other components alter crystallization, so a freezing-point result is not a replacement for direct water measurement. Freezing alone does not necessarily damage the chemical, but thawed material should be fully liquefied, homogenized and checked against the applicable specification.

Low volatility limits rapid evaporation at ambient temperature, but does not prevent exposure to heated vapor or mist. Product isolation may require extraction, washing or engineered vacuum recovery. Reduced pressure does not remove the need to evaluate decomposition, contamination and concentration of reactive residues.

Density and viscosity values require a stated temperature. Mixture behavior can differ from that of the neat solvent, including viscosity and heat of mixing. Adding water therefore affects both process performance and equipment duty.

These descriptive values are not contractual acceptance limits. For the offered assay, water, acidity, color, trace metals and analytical methods, please contact Ataman Kimya.

THERMAL STABILITY AND SOLVENT SUBSTITUTION WITH DMSO DIMETHYL SULFOXIDE

The normal boiling point is not a safe operating-temperature limit. Decomposition can generate heat and gas, and documented incidents show that reactive mixtures can become dangerous below the boiling point. Acids, strong bases, certain salts, metals, oxidizers and electrophiles require mixture-specific compatibility assessment.

Replacement of NMP, DMF or DMAc must consider polymer solubility, water balance, crystallization, product isolation and thermal behavior alongside hazard classification. A satisfactory substitution in cleaning does not prove suitability in membrane casting or an API reaction. Evaluate the entire blend, because added amines or other solvents can control its final hazards.

SECTORS AND INDUSTRIAL APPLICATIONS OF DMSO DIMETHYL SULFOXIDE

Main areas of use:

Pharmaceutical and agrochemical synthesis
Polymer solutions, fibers and membranes
Photoresist and organic-residue removal
Paint and adhesive removal
Analytical laboratories and compound libraries
Cell banking and biological research

DMSO DIMETHYL SULFOXIDE IN CHEMICAL SYNTHESIS

Purpose: Provide a compatible medium for selected transformations.
Function: Dissolve substrates and change ionic solvation.
Performance effect: Can improve homogeneity and reaction rate in suitable systems.
Limitations: Thermal stability, side reactions, residual solvent and product isolation remain process-specific.

DMSO DIMETHYL SULFOXIDE IN POLYMER PROCESSING

Purpose: Prepare compatible polymer dopes or casting solutions.
Function: Solvate suitable polymers and interact with aqueous coagulation systems.
Performance effect: Can support controlled fiber or membrane formation.
Limitations: Polymer identity, concentration, water content and recovery efficiency determine feasibility.

DMSO DIMETHYL SULFOXIDE IN ELECTRONICS AND COATING REMOVAL

Purpose: Remove selected resists, coatings and residues.
Function: Penetrate and swell films with suitable co-components.
Performance effect: Can improve stripping relative to an unsuitable weak solvent.
Limitations: Metal loss, substrate compatibility, bath contamination and rinsing must be measured.

DMSO DIMETHYL SULFOXIDE IN BIOLOGICAL LABORATORIES

Purpose: Prepare compound stocks or protect selected cells during freezing.
Function: Dissolve compatible test compounds and provide cell-permeating cryoprotection.
Performance effect: Can support reproducible dosing or post-thaw recovery.
Limitations: Include solvent controls and validate concentration, exposure time, sterility and biological function.

COSMETIC, FOOD AND PHARMACEUTICAL STATUS OF DMSO DIMETHYL SULFOXIDE

Cosmetics require a clear distinction from medicines. Dimethyl sulfoxide is prohibited in EU cosmetic products under Annex II, entry 338, of Regulation (EC) No 1223/2009. Canada's Cosmetic Ingredient Hotlist also lists it among prohibited ingredients. An inventory name does not override these restrictions.

No E-number food-additive application is proposed for DMSO. Industrial or laboratory supply does not establish authorization for direct food use, food-contact processing or an extraction process. Those applications require a separate, specific legal basis.

In pharmaceutical manufacturing, ICH Q3C lists dimethyl sulfoxide in Class 3. The guideline's general Class 3 treatment accepts up to 50 mg/day without further justification, corresponding to 5000 ppm under Option 1. This is a residual-solvent framework, not an instruction for dosing DMSO or a blanket limit for every formulation.

A prescription 50 % w/w aqueous DMSO medicine has an approved US intravesical indication for symptomatic relief of interstitial cystitis. That authorization belongs to the finished medicinal product and route. It does not authorize industrial solvent for self-treatment, injection or general topical use.

For cell-related applications, purity, microbiological quality, endotoxins where relevant and process documentation must match the intended workflow. Compliance with a pharmacopoeial monograph alone does not make a container a sterile clinical preparation.

WHICH PROBLEMS CAN DMSO DIMETHYL SULFOXIDE HELP SOLVE?

Poor solubility in a selected process
The solvent may allow a homogeneous reaction or stock solution, provided stability and downstream isolation remain acceptable.

Slow or ineffective removal of a compatible film
Swelling and co-solvent action may improve removal, but the exposed substrate must be inspected for damage.

Excessive evaporation during handling
Low ambient volatility can help stabilize solvent composition, although moisture uptake still changes the mixture.

Inconsistent recovery of frozen cells
A matched cryoprotective system can reduce freezing injury, while cell quality, cooling and thawing remain decisive.

THINGS TO CONSIDER WHEN USING DMSO DIMETHYL SULFOXIDE

A common mistake is equating absence of EU CLP classification with absence of exposure risk. DMSO penetrates skin and can enhance absorption of some dissolved substances, depending on their properties and the mixture. It does not automatically transport every dissolved molecule to the same extent.

Match purity and impurity limits to the intended process.
Control water uptake after opening.
Account for heat released when mixing with water.
Assess the complete reaction mixture before heating or concentration.
Confirm plastics, elastomers, seals and coatings are compatible.
Select gloves by tested permeation data for the actual mixture.
Include a solvent-only control in biological assays.
Plan recovery and wastewater treatment before scale-up.

Glove material alone is not a guarantee of protection. Thickness, manufacturer, contact time and dissolved chemicals matter, so a universal statement that all thin nitrile is adequate or inadequate should be avoided. Prevent skin contact and control heated aerosols with suitable engineering measures.

INITIAL FORMULATION APPROACHES FOR DMSO DIMETHYL SULFOXIDE

The following complete mixtures are unvalidated laboratory screening examples. Percentages are by total mixture mass, w/w. They illustrate solvent and amine levels within published application approaches, not guaranteed removal efficiency, safe operating conditions or compatibility with production equipment.

EXAMPLE 1: DMSO DIMETHYL SULFOXIDE IN A LIQUID COATING-REMOVAL SCREEN

Components:

DMSO Dimethyl Sulfoxide: 70.00 %
Diethylene glycol monobutyl ether: 30.00 %
Total: 100.00 %

This unthickened blend evaluates solvent ratio on contained test coupons. It is not a ready-made vertical-surface gel. Thickening, inhibitors or wetting additives would require a new mass balance and separate validation.

Evaluation criteria:

Time to swelling and film release
Removal after a defined contact period
Substrate discoloration, corrosion or softening
Rinsability and residual film
Phase stability and crystallization during storage

Safety note: Avoid skin exposure to the blend and dissolved coating residues. Evaluate the mixture's hazards and flash point, and use suitable gloves, eye protection and ventilation.

EXAMPLE 2: DMSO DIMETHYL SULFOXIDE IN A BASIC PHOTORESIST-REMOVAL SCREEN

Components:

DMSO Dimethyl Sulfoxide: 90.00 %
Monoethanolamine: 10.00 %
Total: 100.00 %

This binary starting mixture isolates solvent and amine effects. It contains no designed corrosion inhibitor and is not validated for copper, aluminum or an actual wafer stack. Use application-appropriate impurity control and coupon testing before considering a working bath.

Evaluation criteria:

Resist remaining after a defined treatment
Copper and aluminum thickness or mass change
Rinse residue and particle redeposition
Water uptake and repeated-use performance
Compatibility and thermal behavior of the spent mixture

Safety note: The amine changes the hazards of the mixture. Prevent skin and eye contact, provide local extraction and establish thermal compatibility before selecting a heated test condition.

DMSO DIMETHYL SULFOXIDE SIMILAR PRODUCTS AND ALTERNATIVES

Compare solvent power, water miscibility, crystallization, recovery requirements and the complete hazard profile together.

DMSO DIMETHYL SULFOXIDE AND NMP, DMF OR DMAC

These amide solvents can serve overlapping applications but are different substances. Compare current classifications and use restrictions with actual dissolution and process performance rather than assuming a direct replacement ratio.

DMSO DIMETHYL SULFOXIDE AND ESTER OR GLYCOL-ETHER SYSTEMS

Esters and glycol ethers may provide co-solvency or alternative film-removal behavior. They bring their own flash points, hydrolysis tendencies and exposure requirements, so a blend must be assessed as a whole.

DMSO DIMETHYL SULFOXIDE AND OTHER CRYOPROTECTANTS

Glycerol and other cryoprotectants can suit particular cells, but permeability and tolerance differ. A successful substitution must preserve post-thaw function as well as an immediate viability count.

Dimethyl sulfone and dimethyl sulfide are not functional substitutes merely because the names are related. Laboratory and pilot trials should confirm any proposed solvent change.

QUALITY CONTROL AND PURCHASING CRITERIA FOR DMSO DIMETHYL SULFOXIDE

Define the application before comparing price. A high assay alone does not describe performance in sensitive manufacturing.

Information to clarify before purchasing:

Intended industry, market and required quality standard
Assay and analytical method
Water by Karl Fischer and sampling controls
Acidity, color and specified sulfur-containing impurities
Crystallization point and relevant optical properties
Metals, anions and particles where required
Biological testing, sterility and endotoxins where applicable
Pharmacopoeial compliance and manufacturing documentation where required
Packaging compatibility, quantity and winter handling
Origin, supply-chain regulatory coverage and batch traceability

A COA reports batch-specific results or conformity. Technical information describes the product profile, while an SDS addresses handling, classification and transport. None proves clinical suitability or sterility unless the corresponding evidence is explicitly included.

Purification, water limits, impurity testing, packaging and transport conditions affect the quotation. Please contact Ataman Kimya for the current specification, availability and delivery terms of the offered material.

STORAGE AND HANDLING OF DMSO DIMETHYL SULFOXIDE

Store tightly closed in compatible packaging, protected from moisture, excessive heat and ignition sources. Choose conditions for the supplied product, since some laboratory products are intentionally stored below the freezing point. Avoid imposing a universal minimum storage temperature on every grade.

Where liquid transfer is required, account for crystallization around 18.5 °C. Thaw using controlled, even warming without open flames or local overheating, then homogenize before sampling. Confirm water and other critical properties after prolonged storage or repeated opening.

Segregate from incompatible oxidizers and reactive reagents. Select transfer lines and seals using compatibility data for the actual solution. Long-term storage stability and packaging-specific shelf life should be confirmed with Ataman Kimya.

Reviewed pure-solvent documentation identifies no dangerous-goods classification under ADR/RID, IMDG or IATA, with no corresponding UN number. This is not a universal statement for every route or mixture, because US domestic combustible-liquid rules can differ. Classify the actual consignment.

Contain spills with compatible inert absorbent, collect contaminated material and prevent entry to drains. Spent DMSO may contain more hazardous solutes than the original solvent and must be managed accordingly.

SAFETY INFORMATION OF DMSO DIMETHYL SULFOXIDE

Reviewed EU supplier documentation states that the pure substance does not meet CLP classification criteria. US supplier documentation can classify it as a Category 4 flammable liquid with H227, combustible liquid. Therefore, absence of an EU hazard pictogram does not mean the solvent cannot burn.

Skin penetration is a practical exposure concern, particularly with hazardous dissolved substances. Use eye protection, protective clothing and chemically resistant gloves selected from permeation data. Avoid inhaling heated vapor and mist, and do not use odor or garlic-like taste as a method of exposure monitoring.

For skin exposure, remove contaminated clothing and wash promptly with soap and plenty of water. Rinse exposed eyes thoroughly and obtain medical advice for persistent symptoms or contact with a hazardous solution. After ingestion, do not induce vomiting and seek medical advice.

Fire response can involve appropriate foam, dry powder, carbon dioxide or water spray according to the site plan. Combustion can generate sulfur and carbon oxides. Thermal decomposition and pressure generation require consideration independently of the flash point.

Avoid uncontrolled discharge and use an authorized waste route for contaminated solvent and packaging. REACH registration of the substance does not replace the supplier-specific assessment of use or applicable local occupational requirements.

SUPPLY OF DMSO DIMETHYL SULFOXIDE FROM ATAMAN KIMYA

Ataman Kimya can be contacted to evaluate dimethyl sulfoxide supply for synthesis, processing, cleaning and laboratory applications. Confirm the offered purity, impurity limits, packaging and documents before matching the material to a sensitive workflow.

Useful details for a quotation request:

Application and destination market
Required standard and critical impurity limits
Water specification and sampling needs
Estimated quantity and packaging
Temperature and transfer constraints
Required quality, safety and regulatory documents

FREQUENTLY ASKED QUESTIONS ABOUT DMSO DIMETHYL SULFOXIDE

What is DMSO Dimethyl Sulfoxide?
A polar aprotic organosulfur solvent used in selected chemical, polymer, cleaning and laboratory applications.

What is its CAS number?
67-68-5.

What is its EC number?
200-664-3.

What are its formula and molecular weight?
C2H6OS and approximately 78.13 g/mol.

Why can the solvent solidify at room temperature?
Pure DMSO freezes at approximately 18.5 °C, so crystallization can occur in cool rooms or lines.

Does freezing automatically mean the batch is unusable?
No. Controlled thawing, homogenization and specification checks determine suitability.

Is it miscible with water?
Yes, and mixing releases heat that must be considered during preparation.

Is DMSO the same as MSM?
No. MSM is dimethyl sulfone, CAS 67-71-0.

Can ordinary DMSO replace DMSO-d6 for NMR?
No direct equivalence should be assumed, because the deuterated solvent is a separate analytical product.

Does it dissolve every material?
No. Solubility depends on the substance and conditions.

Is it permitted in EU cosmetics?
No. Dimethyl sulfoxide is listed in Annex II, entry 338.

What does ICH Class 3 mean here?
It is a residual-solvent category for pharmaceutical manufacturing, not general authorization for medicinal administration.

What concentration is common in cell freezing?
Published cell-culture guidance commonly uses 5-10 % v/v, optimized for the specific cells. This is a volume basis, unlike the mass-based cleaning examples above.

Are all dissolved substances absorbed through skin equally?
No. Enhancement depends on the substance and formulation, although contact must still be prevented.

Are nitrile or butyl gloves always suitable?
Suitability depends on tested permeation, thickness, contact time and the complete solution.

Does the boiling point define a safe heating limit?
No. Reactive mixtures may decompose dangerously below that temperature.

Does pure DMSO always require a UN number?
Reviewed ADR/RID, IMDG and IATA documentation assigns none, but the mixture and route must be assessed.

Which purchase documents matter?
A batch COA, current technical and safety information, and application-specific quality and regulatory evidence.

DMSO DIMETHYL SULFOXIDE - TECHNICAL SUMMARY

Dimethyl sulfoxide combines strong polarity, water miscibility and low ambient volatility in one defined organosulfur molecule. CAS 67-68-5 and EC 200-664-3 identify it, while dimethyl sulfone, dimethyl sulfide and DMSO-d6 require separate identification.

Water, impurities and packaging distinguish commercial materials. Neither a common CAS number nor a high assay establishes fitness for every analytical, electronics or biological task.

Applications include compatible synthesis media, polymer processing, coating removal and cell-specific laboratory procedures. Formulation performance must be verified on the actual substrate or biological system.

Pharmaceutical residual-solvent status is separate from finished medicine authorization and cosmetic restrictions. The EU cosmetic prohibition must not be overlooked when discussing membrane penetration or pharmaceutical uses.

Combustibility, skin exposure, reactive-mixture decomposition and route-specific transport requirements remain important. For the current product specification, supporting documents and supply conditions, please contact Ataman Kimya.

DMSO Dimethyl Sulfoxide can be sourced from ATAMAN KİMYA. For further information and supply inquiries about DMSO Dimethyl Sulfoxide, please contact ATAMAN KİMYA.