Sodium Propylparaben is a specialty cosmetic ingredient belonging to the paraben family. Chemically, it is the sodium salt of propylparaben, also known as propyl 4-hydroxybenzoate. The compound has the molecular formula C₁₀H₁₁NaO₃ and molecular weight 202.18 g/mol.
Sodium Propylparaben is documented as a preservative ingredient and is evaluated in cosmetic formulations based on its chemical identity, purity, physical properties, formulation compatibility and the regulatory requirements of the target market.
Sodium Propylparaben is the sodium salt form of propylparaben. PubChem lists synonyms including Propylparaben Sodium, Sodium Propylparaben, Propyl 4-Hydroxybenzoate Sodium Salt and Sodium Propyl 4-Hydroxybenzoate.
It should be distinguished from neutral Propylparaben, which has CAS 94-13-3 and molecular formula C₁₀H₁₂O₃. Sodium Propylparaben has CAS 35285-69-9 and molecular weight 202.18 g/mol.
Sodium Propylparaben is classified in cosmetic ingredient databases as a preservative. PubChem's cosmetic-ingredient information cites the Cosmetic Ingredient Review and records its cosmetic use classification as preservative.
The sodium salt form can be useful when formulation development requires the properties of a hydroxybenzoate salt. Its suitability depends on the complete formulation, including pH, water phase, other preservative components and processing conditions.
| Property | Value |
|---|---|
| Chemical Name | Propyl 4-Hydroxybenzoate Sodium Salt |
| CAS Number | 35285-69-9 |
| EC Number | 252-488-1 |
| Molecular Formula | C₁₀H₁₁NaO₃ |
| Molecular Weight | 202.18 g/mol |
| Parent Compound | Propylparaben |
| Chemical Class | Hydroxybenzoate / Paraben Salt |
| IUPAC Name | Sodium 4-propoxycarbonylphenolate |
These chemical identity details are supported by PubChem and ECHA.
A current TCI reference material describes Sodium Propylparaben as a white to light-yellow powder to crystal and identifies it as a solid at 20°C. This is a supplier-specific description, so the final SDP appearance specification should be based on the actual commercial material and COA.
A current TCI laboratory reference lists minimum 95.0 area% by HPLC and minimum 95.0% by neutralization titration. This is a specific supplier's research-use specification and should not automatically be copied as SDP's commercial cosmetic specification.
Therefore, the Assay (HPLC) field on the SDP CMS should contain the actual validated SDP specification.
TCI reports a reference melting point of approximately 302°C for its Sodium Propylparaben reference material. Because this is a supplier reference property, it should be treated as technical information rather than automatically used as the SDP release specification.
TCI reports a water solubility reference value of approximately 1,000 g/L at 23°C for its material. Solubility can depend on measurement conditions and material characteristics, so the SDP product specification should be used where an official solubility requirement exists.
Sodium Propylparaben is classified as a preservative in cosmetic ingredient information.
In formulation development, preservation performance depends on multiple factors rather than the ingredient alone. These include formulation pH, water activity, concentration, packaging, manufacturing hygiene and interactions with other ingredients.
When evaluating Sodium Propylparaben as a cosmetic ingredient, formulators should consider:
Preservative efficacy should be established using appropriate formulation-specific testing.
Sodium Propylparaben is specifically listed in Annex V of the EU Cosmetics Regulation under the entry for butyl 4-hydroxybenzoate and its salts / propyl 4-hydroxybenzoate and its salts. The consolidated Annex V identifies Sodium Propylparaben, CAS 35285-69-9, EC 252-488-1 and provides a maximum concentration of 0.14% as acid for the sum of the individual concentrations under the relevant entry. It also contains specific conditions concerning mixtures and certain leave-on products for children under three years of age.
This regulatory information is market- and product-specific. Current legislation should be checked against the finished formulation and target market before making a compliance claim.
For a commercial Sodium Propylparaben Cosmetic Ingredient, quality control may include:
The numerical acceptance criteria should always be taken from the approved SDP specification.
Sodium Propylparaben should be stored according to the approved product specification and SDS.
General handling practices include:
TCI recommends storage at room temperature in a cool and dark place below 15°C and identifies the material as hygroscopic. This is a supplier-specific storage recommendation and should not replace SDP's approved storage conditions.
| Parameter | Specification |
|---|---|
| Appearance | White or colourless crystals / white powder |