Lauryl ether sulfate sodium (12-10-8) Physical and Chemical Properties
Lauryl ether sulfate sodium
An anionic alkyl ether sulfate surfactant (disodium lauryl ether sulfate) commonly used in formulations for detergents and personal care products, specified for procurement, formulation and QC contexts.
| CAS Number | 12-10-8 |
| Family | Alkyl ether sulfates (anionic surfactants) |
| Typical Form | Viscous liquid or aqueous paste |
| Common Grades | EP |
Lauryl ether sulfate sodium (dialkyl ether sulfate disodium salt) is an anionic surfactant of the alkyl ether sulfate structural class. The material is best described as the disodium salt of a sulfated dialkyl ether (IUPAC fragment: disodium;1-dodecoxydodecane;sulfate), combining one or more long hydrophobic C12-derived alkyl chains linked through ether functionality to a sulfate head group. Electronically, the sulfate moiety is a highly delocalized anion stabilized by two sodium counterions in the solid/salt form; the organic portion is strongly hydrophobic and provides surface-active character and micelle-forming tendency in aqueous media.
Functionally this substance behaves as a conventional alkyl ether sulfate: strong anionic character at neutral to alkaline pH (fully dissociated sulfate), pronounced amphiphilicity that yields good aqueous dispersibility as a sodium salt and strong foaming/detergency, and a preference to partition into hydrocarbon phases absent counterion-driven solubilization. The ether linkage confers greater hydrolytic stability relative to ester analogues, but the sulfate ester can undergo desulfation or cleavage under extreme acidic or strongly alkaline hydrolytic conditions or at elevated temperatures; oxidative cleavage of the alkyl chains can occur under strongly oxidizing conditions. In practical formulations, performance is strongly influenced by counterions (Ca2+, Mg2+) and by co-surfactants, electrolytes and pH.
Common commercial grades reported for this substance include: EP.
Basic Physical Properties
Solubility and Hydration
As a disodium alkyl ether sulfate, the compound is an anionic surfactant that is readily dispersed and solubilized in water at typical use concentrations, forming micelles and surface-active aggregates. Solubility and critical micelle concentration depend strongly on chain distribution, formulation ionic strength and temperature; the sodium counterions favor good aqueous solubility relative to organic or multivalent counterions.
No experimentally established value for this property is available in the current data context.
Thermal Stability and Decomposition
Thermal behavior is characteristic of long-chain organic sulfate salts: the material will not have a well-defined low-pressure boiling point and typically undergoes degradation (desulfation, cleavage of the ether linkage, oxidative decomposition and charring) on heating rather than simple vaporization. Thermal stability is limited relative to inorganic salts and is reduced in the presence of strong acids, bases, or oxidants.
No experimentally established decomposition temperature or thermal stability numeric value is available in the current data context.
Chemical Properties
Complex Formation and Coordination
The sulfate headgroup strongly coordinates with cations via ion-pairing and electrostatic interactions. Interaction with divalent cations (notably \( \mathrm{Ca}^{2+} \) and \( \mathrm{Mg}^{2+} \)) promotes ion-pair formation and can lead to reduced solubility or precipitation (water hardness incompatibility). Sodium counterions provide charge balance in the isolated salt form; in aqueous phase the anionic sulfate exists as solvated sulfate species with mobile counterions.
Reactivity and Stability
Chemically the material is relatively stable under neutral conditions but can undergo the following class-typical reactions: - Hydrolysis/desulfation under strongly acidic or strongly alkaline conditions, accelerated at elevated temperature. - Oxidation of alkyl chains by strong oxidizing agents, leading to chain scission and formation of oxygenated fragments. - Ion-exchange or complexation with multivalent cations, reducing surfactant effectiveness and causing turbidity or precipitation.
Compatibility with oxidizers and strong acids/bases is limited; formulation compatibility testing is required for specific process conditions.
Molecular Parameters
Molecular Weight and Composition
- Molecular formula: C24H50Na2O5S
- Molecular weight: 496.7 \(\mathrm{g}\,\mathrm{mol}^{-1}\)
- Exact mass: 496.31743443 \(\mathrm{Da}\)
- Monoisotopic mass: 496.31743443 \(\mathrm{Da}\)
- Topological polar surface area (TPSA): 97.9 \(\text{Å}^2\)
- Heavy atom count: 32
- Compound complexity: 254
These values reflect a disodium salt composed of a long-chain dialkyl ether backbone bearing a sulfate headgroup; the relatively large TPSA derives from the sulfate and ether oxygens and contributes to aqueous solvation of the headgroup while the long alkyl chains maintain strong hydrophobic character.
LogP and Ionization State
No experimentally established value for logP is available in the current data context.
Ionization state: the substance is supplied and represented as the disodium salt of a sulfate ester. In aqueous solution the sulfate group is ionized (anionic), with sodium as the counterion; the overall formulated solid is electrically neutral when counterions are included (formal charge reported as 0). Relevant computed counts: hydrogen bond donor count 0; hydrogen bond acceptor count 5; rotatable bond count 22.
Identifiers and Synonyms
Registry Numbers and Codes
- CAS number: 12-10-8
- InChI: InChI=1S/C24H50O.2Na.H2O4S/c1-3-5-7-9-11-13-15-17-19-21-23-25-24-22-20-18-16-14-12-10-8-6-4-2;;;1-5(2,3)4/h3-24H2,1-2H3;;;(H2,1,2,3,4)/q;2*+1;/p-2
- InChIKey: SMVRDGHCVNAOIN-UHFFFAOYSA-L
- SMILES: CCCCCCCCCCCC O CCCCCCCCCCCC . [O-]S(=O)(=O)[O-].[Na+].[Na+]
Synonyms and Structural Names
Depositor-supplied synonyms and alternative names include:
- lauryl ether sulfate sodium
- disodium;1-dodecoxydodecane;sulfate
- 1335-72-4
- Sodiumlaurylethersulfate
- SCHEMBL15284
- C24H50Na2O5S
- FS71695
Removed or alternative synonyms recorded include variants such as "Sodium lauryl ether sulfate", "Sodium laureth sulfate", "disodium 1-dodecoxydodecane sulfate" and other registry strings; these reflect naming and indexing variants encountered for related materials.
Industrial and Commercial Applications
Use as Salt Form or Excipient
As the sodium salt of an alkyl ether sulfate, this material functions principally as an anionic surfactant/excipient. The salt form improves water dispersibility and handling relative to free acid forms and is commonly selected for formulations that require foaming, wetting, emulsification or detergent action. The disodium form is compatible with many aqueous processing operations, subject to limitations with hard water and oxidizing agents.
Representative Use Cases
Representative application classes where materials of this structural type are widely applied include:
- Personal care and cosmetic formulations (shampoos, body washes) as cleansing and foaming agents.
- Household and institutional liquid detergents and cleaners for surfactant-driven removal of oils and soils.
- Industrial cleaning formulations where an anionic surfactant is required for emulsification and wetting.
Classification metadata associated with consumer and household product contexts is consistent with these typical uses.
If a concise product-specific application summary is required for procurement or formulation, selection should be based on exact chain distribution, residual ethoxylation, and purity/grade characteristics.
Safety and Handling Overview
Toxicological Considerations
Materials of the alkyl ether sulfate class are generally irritant to eyes and mucous membranes and can produce skin irritation at sufficient concentrations or prolonged exposure; they are not highly volatile and primary exposure pathways are dermal and ocular contact or inhalation of aerosols. Aquatic toxicity is a common concern for surfactants; avoidance of uncontrolled discharge to aquatic environments is recommended. No specific LD50 or acute numeric toxicological endpoints are provided in the current data context.
For detailed hazard classification, exposure limits and toxicological endpoints, refer to the product-specific Safety Data Sheet (SDS) supplied by the manufacturer.
Storage and Handling Guidelines
Recommended handling practices for anionic surfactant salts:
- Store in a cool, dry, well‑ventilated area away from strong acids, strong bases and strong oxidizing agents.
- Avoid formation of dust and aerosols; use local exhaust or respiratory protection if dust/aerosol generation is possible.
- Prevent contamination with multivalent cations (hard water) where precipitate formation is undesirable.
- Use standard chemical protective equipment: gloves, eye protection and suitable protective clothing when handling concentrated material.
For detailed hazard, transport and regulatory information, users should refer to the product-specific Safety Data Sheet (SDS) and local legislation.
