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Sodium lauryl sulfate (SLS; CAS 151-21-3) is a widely used anionic surfactant and detergent, available commercially as powders, flakes, pellets and aqueous solutions.
The powder form is favored for storage, transport efficiency and use in manufacturing of cleaning products, personal-care formulations, and laboratory reagents.
This review covers SLS powder chemistry, production routes, physical–chemical properties, formulation and application examples, analytical methods and quality control, human health considerations and dermatological effects, ecotoxicology and environmental fate, regulatory status, handling and storage for powder forms, and typical specification/grade considerations.
Chemical identity and molecular description
Chemical formula: C₁₂H₂₅NaO₄S (commonly represented as CH₃(CH₂)₁₁OSO₃⁻ Na⁺).
Molecular weight: ≈ 288.38 g·mol⁻¹.
Structural features: a 12-carbon linear alkyl chain (lauryl / dodecyl) attached to a sulfate group; the molecule is an anionic surfactant (sulfate headgroup, sodium counterion) that forms micelles above its critical micelle concentration (CMC).
Graphical structures and skeletal formulae are widely available in chemical databases.
Ionization / pKa: As a sodium salt of a strong sulfuric acid ester, the sulfate head is fully ionized under normal aqueous pH; no relevant pKa in the usual formulation range.
Physical and physicochemical properties (powder-relevant)
Appearance (powder form): white to off-white granular powder, flakes or needle-like crystals depending on manufacturing and drying method. Commercial powders commonly range from ca. 80–99% active SLS (technical grades often 92–95%).
Melting / decomposition: reported melting points around ~204 °C (decomposes on further heating), though technical materials (mixtures of alkyl chain lengths) may have complex thermal behavior.
Solubility: moderately to highly soluble in water; solubility increases with temperature and is strongly affected by particle size and grade (powders dissolve more slowly than liquid solutions).
Typical quoted solubility values: ~15 g per 100 mL at 20 °C for the pure sodium salt (varies with grade).
CMC and surface activity: SLS has a low CMC (in the low mmol·L⁻¹ range depending on ionic strength), conferring excellent foaming and wetting properties. Exact CMC values depend on temperature, ionic strength and presence of cosurfactants.
Partitioning: log P (octanol/water) for the dodecyl sulfate anion is low-to-moderate (reported log Pow ≈ 1.6), indicating limited bioaccumulation potential but appreciable hydrophobic interactions in membranes or with organic matter.
Manufacture and production routes (industrial powder production)
Primary industrial routes produce SLS in two main stages:
Preparation of lauryl (dodecyl) alcohol or fatty feedstock: derived from hydrogenation of lauric acid (from coconut oil, palm kernel oil) or derived from petrochemical sources.
Many commercial materials are mixtures (C10–C14) from natural fatty feedstocks—hence product variability (often marketed as sodium lauryl sulfate or sodium dodecyl sulfate interchangeably when C12 dominates).
Sulfation then neutralization: lauryl alcohol is sulfated (commonly with chlorosulfonic acid, sulfur trioxide, or sulfuric acid derivatives) to form lauryl sulfate acid (the sulfate ester), then neutralized with sodium hydroxide or soda ash to produce the sodium salt.
The product is concentrated, filtered, and dried (spray-drying, drum-drying, or crystallization) to yield powder/granular forms.
Powder particle size and moisture content are controlled to meet grade specifications.
Manufacturers may adjust chain-length composition, neutralization degree, and add processing aids to produce technical (detergent), NF/FCC/pharmaceutical or laboratory reagent grades.
Commercial grades and powder specifications
Common commercial grades (examples; suppliers vary):
Technical grade (industrial detergents): high active percentage (≥90–96%), typically sold as coarse powder or granular.
Used in bars, detergents and industrial cleaners.
Cosmetic/personal care grade (NF, FCC, cosmetic): purified to limits for color, chloride/sulfate inorganic salts, and specific impurities; often designed for low odor and consistent viscosity/foaming in formulations.
Laboratory / analytical reagent grade (≥98–99%): used for electrophoresis (SDS) and biochemical applications (SDS-PAGE) where defined purity and consistent ionic strength are required.
Typical powder specification parameters include active content (%), moisture (%), inorganic salts (Na₂SO₄/NaCl), viscosity of aqueous solution, pH (1% solution), color (APHA/Pt-Co), and presence of peroxide or residual acid. Sample limits and ranges are provided on supplier product pages and SDSs.
Mechanism of action and functional performance
As an anionic surfactant SLS reduces surface tension and stabilizes micelles that solubilize oils and particulates, enabling removal from solid surfaces or skin.
It exerts wetting, emulsification, foaming, and detergency.
In biochemical labs, SDS denatures proteins by binding to peptide backbones and imparting negative charge (SDS-PAGE uses this property).
Powder form enables economical handling and dry blending in manufacturing lines.
Formulation uses and applications
Household & Industrial cleaning: laundry detergents, dishwashing liquids, multi-purpose cleaners, degreasers (powder enables dosing into dry blends).
Personal care: shampoos, body washes, toothpastes (less common in premium skin care due to potential irritation), bubble baths and bath bombs (powder sold to hobbyists and formulators). Concentrations vary widely: industrial cleaners may contain high % SLS; personal care products typically much lower (e.g., 5–30% in raw shampoo bases, lower in finished product).
Pharmaceutical & laboratory: SDS is used as an excipient, emulsifier, and in protein electrophoresis (SDS-PAGE), nucleic acid extraction buffers and sample lysis solutions. Powder reagent grade is standard in labs.
Industrial processes: wetting agents, textile pre-treatment, oilfield chemistries, flotation agents in mining, ceramics and metalworking fluids.
SAFETY INFORMATION ABOUT SODIUM LAURYL SULFATE POWDER
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
