ELTESOL SC 40/SODIUM CUMENE SULPHONATE

Sodium cumene sulphonate (SCS) is an anionic aromatic sulfonate produced by sulfonation of cumene (isopropylbenzene) followed by neutralization to the sodium salt. 
Its principal role in modern formulations is as a hydrotropic solubilizer: it improves solubility of hydrophobic actives and nonionic surfactants, depresses cloud points, adjusts viscosity and aids clear liquid product stability at elevated temperatures. 
Eltesol SC 40 is a branded aqueous solution containing approximately 40% active sodium cumene sulphonate and is widely used in personal care and household product manufacturing.
CAS registry numbers (reported in various supplier & database records):
28348-53-0 — commonly cited CAS for sodium cumenesulfonate in supplier databases and chemical catalogs.
15763-76-5 — appears in older records and some vendor lists for p‑cumenesulfonate derivatives.
32073-22-6 — also reported in some product listings; several sources cross-reference multiple CAS numbers due to isomeric forms or differing salt / hydrated states.
Synonyms and related names:
Sodium cumenesulfonate,Sodium cumene sulfonate,Sodium cumene sulphonate
Sodium isopropylbenzenesulfonate,Sodium p‑cumenesulfonate,Cumenesulfonic acid sodium salt
Sodium cumyl benzene sulfonate,Sodium 4‑isopropylbenzenesulfonate

Molecular structure and basic chemistry
Sodium cumene sulphonate is the sodium salt of cumenesulfonic acid. 
Structurally, it is an aromatic sulfonate where the benzene ring carries an isopropyl substituent (cumene = isopropylbenzene) typically at the para position (p‑cumene sulfonate is common), and a sulfonate group (–SO₃⁻) that is ionically paired with sodium.
Key chemical features that determine performance:
Aromatic hydrophobic ring with isopropyl group: confers hydrophobic interactions with non-ionic or hydrophobic actives and contributes to solubilization capacity.
Strongly polar sulfonate head: provides high water solubility in its sodium salt form and good ionic strength in aqueous solution.
Anionic character: influences compatibility with cationic species and ionic strength-dependent behaviors.
The combination of a hydrophobic aromatic fragment and a strongly water-soluble ionic head explains why SCS behaves as an effective hydrotrope: it can interact with both hydrophobic and hydrophilic domains, altering micelle formation, cloud points and solubilization equilibria.
Manufacturing and production methods
General route
Sulfonation of cumene (isopropylbenzene): Cumene is treated with sulfur trioxide (SO₃) or oleum (a solution of SO₃ in concentrated sulfuric acid) under controlled conditions to yield cumenesulfonic acid (the arylsulfonic acid). 
Reaction temperature, stoichiometry and the presence of solvents control regioselectivity and degree of sulfonation.
Neutralization: The resultant cumenesulfonic acid is neutralized with sodium hydroxide (NaOH) to produce the sodium salt (sodium cumene sulphonate). 
Neutralization must be controlled to target pH and to limit formation of by‑products.
Purification and formulation: The crude salt is purified (if required) by extraction, filtration and washing. 
For Eltesol SC 40, the purified sodium cumene sulphonate is formulated as a 40% w/w aqueous solution and may contain small amounts of stabilizers, corrosion inhibitors or processing aids depending on the supplier’s formulation and intended applications.
Process considerations
Sulfonation control: Sulfonation of aromatic substrates is exothermic; temperature control and staged addition of sulfonating agent are critical to minimize polynuclear sulfonation and side reactions.
Isomer distribution: Sulfonation can yield ortho, meta and para isomers; para is often favored due to steric and directing effects of the isopropyl group, but reaction conditions (temperature, solvent, SO₃ concentration) influence distribution.
Neutralization and salt formation: Excess NaOH can lead to high ionic strength solutions; insufficient neutralization leaves residual acid which affects product performance and corrosivity.
Waste and effluent management: Sulfonation processes generate acidic effluents and sulphur-containing wastes; neutralization, sulfite management and appropriate treatment are necessary to comply with environmental regulations.

Typical product grades and the commercial Eltesol SC 40 formulation
Eltesol SC 40 is a commercially available grade that contains roughly 40% sodium cumene sulphonate in water. Typical attributes (supplier technical datasheets) include:
Active matter (sodium cumene sulphonate): 39–41% w/w
Physical form: pale yellow to light amber clear liquid
Typical density: ~1.15–1.20 g·cm⁻³ at 20–25 °C (specific supplier value often ~1.17 g·cm⁻³)
Viscosity: low, often tens of mPa·s (typical ~50 mPa·s depending on temp and exact composition)
pH (neat or 10% w/w solution): mildly alkaline (depends on neutralization; suppliers often report pH ~7–10)
Color: pale yellow; stability to storage depends on impurities and oxidation products
Commercial grades may be offered in differing active concentrations (e.g., 30–50%), as solid powders (≥90% purity sodium salt) or as aqueous solutions for ease of handling.

Physicochemical properties and typical analytical values
Below are representative physicochemical properties; actual values must be confirmed from the supplier’s certificate of analysis (COA) for each batch.
Molecular formula: C₉H₁₁NaO₃S
Molecular mass: ≈ 222.24 g·mol⁻¹
Appearance: white crystalline powder (solid grade) or pale yellow clear liquid (40% solution)
Solubility: Highly soluble in water. Insoluble or sparingly soluble in nonpolar organic solvents. Solubility improves with temperature and ionic strength modifications.
pKa: The sulfonic acid functional group (when protonated) is a strong acid with pKa typically < 1; in practice the sulfonate exists as a fully ionized anion in neutral/alkaline aqueous solutions.
pH (1% w/w solution): typically neutral to slightly alkaline depending on the exact salt and residual alkali.
Specific gravity (40% solution): ≈ 1.15–1.20 g·cm⁻³ at 20 °C
Viscosity (40% solution): ~30–80 mPa·s (supplier dependent)
Surface activity: Sodium cumene sulphonate is not primarily used as a foaming surfactant; its hydrotropic and coupling properties influence micelle behavior rather than generate high foam.
CMC (critical micelle concentration): As an aromatic sulfonate, it can exhibit micelle-like aggregation at higher concentrations, but as a hydrotrope its principal action often occurs below classical CMC values—precise CMC depends on ionic strength and temperature.

SAFETY INFORMATION ABOUT ELTESOL SC 40/SODIUM CUMENE SULPHONATE

First aid measures:
Description of first aid measures:
General advice:
Consult a physician. 
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
 
If inhaled:
If breathed in, move person into fresh air. 
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately. 
Wash off with soap and plenty of water.
Consult a physician.
 
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
 
If swallowed:
Do NOT induce vomiting. 
Never give anything by mouth to an unconscious person. 
Rinse mouth with water. 
Consult a physician.
 
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
 
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment. 
 
Avoid breathing vapours, mist or gas. 
Evacuate personnel to safe areas.
 
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
 
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste. 
Keep in suitable, closed containers for disposal.
 
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
 
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place. 
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
 
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
 
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles. 
Faceshield (8-inch minimum). 
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
 
Skin protection:
Handle with gloves. 
Gloves must be inspected prior to use. 
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product. 
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. 
Wash and dry hands.
 
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
 
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls. 
 
If the respirator is the sole means of protection, use a full-face supplied air respirator. 
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so. 
Do not let product enter drains.
Discharge into the environment must be avoided.
 
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions. 
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
 
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company. 
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product