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Sodium dodecylbenzenesulfonate (SDBS) is a high-performance anionic surfactant of the linear alkylbenzene sulfonate (LAS) family produced by sulfonation of linear dodecylbenzene followed by neutralization with sodium hydroxide.
It is widely used as a detergent, emulsifier, wetting agent, dispersant and antistatic agent across household, industrial, textile, paper and specialty chemical applications.
Common name: Sodium dodecylbenzenesulfonate (often abbreviated SDBS or SDBS*)
CAS number: 25155-30-0.
Chemical identity and structure
SDBS is an anionic surfactant consisting of a linear C₁₂ alkyl chain attached to a benzene ring (linear dodecylbenzene, LDB) that is sulfonated to give the sulfonic acid (dodecylbenzenesulfonic acid, DBSA), then neutralized to the sodium salt.
The typical commercial product is a mixture of positional isomers (ortho/meta/para substitution on the benzene ring and small distribution of alkyl chain branching depending on the LAB feedstock), but modern commercial products target linear alkyl chains (linear alkylbenzene sulfonates, LAS) because of better biodegradability than branched alternatives.
Chemical formula and basic identifiers are reported in major chemical databases.
Structural notation (typical): CH₃(CH₂)₁₁–C₆H₄–SO₃⁻ Na⁺ (with the alkyl chain attached at the 2-position or other ring positions depending on the alkylation pattern).
Physical and chemical properties
(typical ranges for commercial SDBS, note that specific values depend on degree of purity, solid vs slurry form, “soft” vs “hard” type and presence of isomeric mixtures)
Appearance: white to light yellow powder, flakes, beads or viscous slurry (aqueous).
Solubility: highly soluble in water (forms clear to slightly opalescent solutions depending on concentration and ionic strength); insoluble in nonpolar solvents.
pKa: sulfonate group is a strong acid — in the sodium salt form it is fully dissociated under normal environmental pH (no measured pKa relevant for the salt).
Critical micelle concentration (CMC): in the low mM range (literature values vary with ionic strength and temperature; commercial LAS products show micellization and foaming typical for anionic surfactants).
Surface tension reduction: effective in lowering water surface tension, producing good wetting and foaming characteristics.
Thermal stability: stable at normal processing temperatures; decomposition at elevated temperatures with evolution of SOₓ species for the sulfonate group.
Hygroscopicity: commercial sodium alkylbenzene sulfonate powders are hygroscopic and may be delivered as slurry or dried powder depending on product form.
Manufacturing and large-scale production
Feedstocks and upstream chemistry
Industrial production begins with petroleumderived feedstocks: linear paraffins (e.g., C₁₂ paraffin or internal olefins derived from C₁₂) are dehydrogenated to olefins and then used to alkylate benzene, producing linear alkylbenzenes (LAB).
LAB production methods include HF and zeolite or solid acid catalysis variants; dehydrogenation/alkylation remains the basis of modern LAB manufacture.
Sulfonation to DBSA
LAB is sulfonated using sulfonating agents such as sulfur trioxide (SO₃), fuming sulfuric acid (oleum), or concentrated sulfuric acid to give dodecylbenzenesulfonic acid (DBSA).
Electrophilic aromatic sulfonation introduces the –SO₃H onto the benzene ring; process control (temperature, SO₃ stoichiometry, mixing) impacts degree of sulfonation and side reactions.
Neutralization and finishing
The DBSA is neutralized with NaOH to produce the sodium salt (SDBS).
The neutralized product is commonly furnished as a 25–40% aqueous slurry, which can be dried (drum drier, spray dryer) to flakes, beads or powdered product depending on customer requirements.
Powder production requires careful control of viscosity and drying because concentrated Na-salt solutions become very viscous at high active matter content; specialized powder processes and anti-caking measures are used.
Patents and industrial literature describe methods for producing high-active, transportable powders and beads.
Industrial grades and commercial forms
Industry distinguishes “soft” and “hard” types (and variations by active matter content):
Soft type: typically higher linearity and a more liquid/slurry product; often used as raw material for formulations.
Hard type: often refers to versions processed to flakes / powders / beads, sometimes with additives to reduce hygroscopicity; used where solid dosing is required.
Catalogs list several CAS or product codes for these types; some commercial product sheets may list alternate CAS identifiers for pre-formulated mixtures.
Analytical methods and quality control
Quality control typically assesses: active matter content (wt% SDBS), alkyl chain distribution (GC of alkylbenzenes), sulfonation degree, sodium content, moisture, ash, and presence of halogenated impurities (if any).
Standard techniques include:
GC-MS or GC-FID after suitable derivatization or solvent extraction for alkylbenzene profile.
Ion chromatography (IC) for anionic content and counterion analysis.
Titration for active sulfonate content and free acid/alkali.
FT-IR for sulfonate functional group confirmation.
Surface tension and foam tests for functional properties (du Noüy ring, Ross–Miles foam test).
Method details and specifications are provided in product technical sheets and regulatory dossiers.
Performance characteristics and mechanism of action
SDBS lowers interfacial tension at air-water and oil-water interfaces by orienting at the interface with the hydrophobic dodecyl tail in oil/air and the sulfonate head in water.
This results in:
Wetting: improved penetration and removal of particulate and proteinaceous soils.
Emulsification and dispersion: stabilizes oil droplets and particulate suspensions.
Foaming: strong foaming ability (often desirable in detergents but controlled in industrial formulations).
Detergency: combines wetting, emulsification and micellar solubilization to remove oily and particulate soils.
Performance metrics (e.g., detergency vs temperature, foaming vs hardness) are formulation-dependent; LAS surfactants like SDBS are sensitive to water hardness (calcium and magnesium reduce solubility and can precipitate at high concentrations without builders).
Applications (industrial and consumer)
SDBS is a versatile anionic surfactant used in many sectors:
Household and laundry detergents: as primary anionic surfactant for solids/liquids; good removal of particulate and oily stains (widely used worldwide historically as LAS/C12 fraction).
Industrial cleaning agents and degreasers: heavy-duty cleaners, metal degreasing, parts washers.
Textile processing and wetting/antistatic treatments: used in scouring, emulsifying dyes, antistatic finishes on synthetic fibers.
Paper and pulp deinking and processing: dispersant and wetting agent in paper recycling.
Emulsifier/dispersant in coatings, agrochemicals and rubber compounding: assists mixing and dispersion of active ingredients and pigments.
Specialty uses: flotation agents in mining, defoamers or wetting agents in formulation chemistry, and some laboratory uses where an anionic surfactant is required
SAFETY INFORMATION ABOUT SODIUM DODECYLBENZENESULFONATE
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
