Sodium Stearyl Sulfate is an anionic fatty alcohol sulfate surfactant used in cosmetic and personal-care formulations for cleansing and other surface-active applications. It is the sodium salt of stearyl sulfate and contains a saturated C18 hydrocarbon chain.
Sodium Stearyl Sulfate is also known as Sodium Octadecyl Sulfate and Sulfuric Acid Monooctadecyl Ester Sodium Salt. Its primary CAS number is 1120-04-3, molecular formula is C18H37NaO4S, and molecular weight is approximately 372.50 g/mol.
The molecule has an amphiphilic structure consisting of a hydrophobic stearyl chain and a hydrophilic sulfate group. This structure gives Sodium Stearyl Sulfate surface-active characteristics and allows it to participate in cleansing and interfacial processes.
In cosmetic formulations, Sodium Stearyl Sulfate can be evaluated for suitable cleansing and surfactant systems. Its actual performance depends on concentration, formulation composition, pH, processing conditions and the characteristics of the commercial grade.
Sodium Stearyl Sulfate is the sodium salt of stearyl sulfate and belongs to the fatty alcohol sulfate family. The stearyl chain contains 18 carbon atoms and is saturated.
The Cosmetic Ingredient Review identifies Sodium Stearyl Sulfate as the sodium salt of stearyl sulfate, with the structural representation CH₃(CH₂)₁₇OSO₃Na, and identifies its function as a cleansing agent.
PubChem identifies Sodium Stearyl Sulfate as sodium octadecyl sulfate and provides the C18H37NaO4S molecular formula and approximately 372.5 g/mol molecular weight.
Sodium Stearyl Sulfate contains a saturated C18 alkyl chain attached to a sulfate group. Sodium acts as the counter-ion.
| Parameter | Details |
|---|---|
| INCI Name | Sodium Stearyl Sulfate |
| Product Name | Sodium Stearyl Sulfate |
| CAS Number | 1120-04-3 |
| Additional CAS Identifier | 65151-89-5 |
| EC Number | 214-295-0 |
| Chemical Name | Sodium Octadecyl Sulfate |
| Alternative Name | Sulfuric Acid Monooctadecyl Ester Sodium Salt |
| Chemical Class | Fatty Alcohol Sulfate |
| Surfactant Type | Anionic |
| Carbon Chain | C18 |
| Chain Type | Saturated |
| Counter-Ion | Sodium |
| Molecular Formula | C18H37NaO4S |
| Molecular Weight | 372.50 g/mol |
| Category | Cosmetic Ingredient |
The Sodium Stearyl Sulfate molecule contains:
Its structural formula can be represented as:
CH₃(CH₂)₁₇OSO₃Na
The saturated C18 hydrocarbon portion provides hydrophobic character, while the sulfate group provides the ionic and hydrophilic portion of the molecule.
Sodium Stearyl Sulfate is an anionic fatty alcohol sulfate surfactant.
The molecule has both hydrophobic and hydrophilic portions, allowing it to participate at interfaces between water and other materials.
Potential formulation functions include:
For cosmetic use, the documented primary function is cleansing/surfactant activity.
Sodium Stearyl Sulfate is recognized as a cleansing ingredient in cosmetic applications.
Its amphiphilic structure enables interaction with water and hydrophobic materials, supporting their dispersion during a cleansing process.
Potential applications include:
The final cleansing characteristics depend on the complete formulation.
As an anionic surfactant, Sodium Stearyl Sulfate can contribute surface-active properties to aqueous formulation systems.
The sulfate group interacts with the aqueous phase while the long hydrocarbon chain provides hydrophobic interactions.
This amphiphilic behavior makes the ingredient relevant to formulation systems where surface activity is required.
Sodium Stearyl Sulfate can be evaluated in selected shampoo and hair-cleansing formulations.
Potential applications include:
Formulation development should evaluate:
Sodium Stearyl Sulfate can be evaluated for suitable rinse-off facial cleansing systems.
Potential applications include:
The complete formulation should be evaluated for pH, cleansing characteristics, sensory properties and stability.
Sodium Stearyl Sulfate can be evaluated for suitable body-cleansing formulations.
Potential applications include:
Potential personal-care applications include:
Application suitability should be determined by formulation testing and the intended product type.
These should not be treated as identical ingredients.
Sodium Stearyl Sulfate is the individual sodium salt of stearyl sulfate.
Sodium Cetearyl Sulfate is a mixture of sodium cetyl sulfate and sodium stearyl sulfate. The Cosmetic Ingredient Review specifically describes Sodium Cetearyl Sulfate as the sodium salt of a mixture of cetyl and stearyl sulfate.
PubChem separately identifies Sodium Cetearyl Sulfate as CAS 59186-41-3.
When evaluating Sodium Stearyl Sulfate, formulators may consider:
The appropriate acceptance criteria should be based on the specification of the actual commercial grade.
A general formulation-development approach may include:
Actual processing parameters should be established based on the selected grade and finished-product requirements.
The solution and dispersion characteristics of Sodium Stearyl Sulfate can depend on:
Therefore, formulation-specific solubility and dispersion testing should be performed before finalizing a manufacturing process.
The physical form of Sodium Stearyl Sulfate is grade-dependent.
Commercial materials may be supplied as solid or powder-type materials depending on manufacturing process, purity and formulation grade.
For an SDP product page, the final appearance specification should be taken from the actual commercial product's approved specification and COA.
Quality-control parameters may include:
Recommended storage considerations include:
Sodium Stearyl Sulfate is an anionic C18 fatty alcohol sulfate used for cleansing and surface-active applications.
For commercial sourcing, manufacturers and formulators can evaluate:
When sourcing Sodium Stearyl Sulfate, buyers may consider:
For bulk procurement, the required specification should be confirmed before commercial supply.
Important procurement information may include:
Sodium Stearyl Sulfate is an anionic fatty alcohol sulfate surfactant and the sodium salt of stearyl sulfate.
The INCI name is Sodium Stearyl Sulfate.
The primary CAS number is 1120-04-3. PubChem also lists 65151-89-5 as another CAS identifier.
The molecular formula is C18H37NaO4S.
The molecular weight is approximately 372.50 g/mol.
It is an anionic fatty alcohol sulfate surfactant.
The characteristic stearyl chain contains 18 carbon atoms.
Yes. The characteristic stearyl chain is saturated.
The documented cosmetic function includes cleansing/surfactant activity.
It can be evaluated for suitable hair-cleansing and rinse-off formulations.
It can be evaluated for appropriate rinse-off facial cleansing systems.
It can be evaluated for suitable body-cleansing formulations.
No. Sodium Cetearyl Sulfate is a mixture of sodium cetyl sulfate and sodium stearyl sulfate, whereas Sodium Stearyl Sulfate is the individual C18 stearyl sulfate sodium salt.
No. Both have C18 chains, but Sodium Stearyl Sulfate has a saturated chain whereas Sodium Oleyl Sulfate has an unsaturated chain.
| Parameter | Specification |
|---|---|
| Appearance | Creamy white to pale yellow |