Methylparaben is a widely recognized paraben-type cosmetic ingredient used primarily as an antimicrobial preservative in personal care and cosmetic formulations. It is chemically known as methyl 4-hydroxybenzoate and has the molecular formula C₈H₈O₃ and molecular weight 152.15 g/mol. Its CAS Number is 99-76-3 and EC Number is 202-785-7.
Methylparaben is characterized as a colourless crystalline material or white crystalline powder. The International Pharmacopoeia identifies it as an antimicrobial preservative and reports that it is very slightly soluble in water while being soluble in boiling water and freely soluble in ethanol.
Methylparaben is the methyl ester of 4-hydroxybenzoic acid. It belongs to the paraben family, which includes several hydroxybenzoate esters used as preservative ingredients.
Its chemical structure provides characteristics that make it useful in preservation systems for cosmetic and personal care formulations. Methylparaben is commonly considered when formulators require an established paraben-based preservative component.
The material is also known as:
Methylparaben functions primarily as an antimicrobial preservative ingredient. Preservation is important for many cosmetic formulations containing water or other components that may support microbial growth.
Its use can help formulate products with appropriate microbiological quality when incorporated into a properly designed preservation system.
The performance of Methylparaben depends on the complete formulation, including concentration, pH, water phase, other preservative components, packaging and manufacturing conditions.
Methylparaben can be considered for a range of cosmetic and personal care formulations, including:
Methylparaben is particularly relevant when formulators are developing preservation systems using hydroxybenzoate ester ingredients.
Methylparaben should be evaluated as part of the complete preservation system rather than as an isolated ingredient. Compatibility with other preservatives, surfactants, emulsifiers, fragrances and active or functional ingredients should be assessed during formulation development.
Methylparaben has limited water solubility. The International Pharmacopoeia describes it as very slightly soluble in water, while reporting greater solubility in boiling water and free solubility in ethanol.
This property is important when designing the manufacturing process and determining how the ingredient will be incorporated into a formulation.
The performance of preservative systems can be affected by formulation pH. The finished formulation should therefore be evaluated at its intended pH rather than relying solely on the characteristics of the individual raw material.
Appropriate processing conditions should be selected to achieve uniform distribution and dissolution or dispersion where required. The actual manufacturing procedure will depend on the formulation type and the other ingredients present.
Formulators should evaluate compatibility with:
Methylparaben has the molecular formula C₈H₈O₃ and molecular weight 152.15 g/mol. It is generally described as a colourless crystalline material or white crystalline powder.
Its reported melting range is around 125–128°C, while published chemical-property data report a melting point of approximately 125°C or higher depending on the reference and measurement conditions.
Methylparaben is only slightly soluble in water. This characteristic should be taken into account during formulation development, particularly for aqueous cosmetic products.
For commercial cosmetic ingredient supply, Methylparaben should be controlled against a documented specification appropriate to the supplied grade.
The 2025 International Pharmacopoeia specifies that Methyl hydroxybenzoate contains not less than 99.0% and not more than 101.0% of C₈H₈O₃, calculated with reference to the dried substance.
Quality evaluation may include:
The exact limits used on an SDP product page should correspond to the actual approved SDP specification or COA rather than a generic value from another manufacturer.
Methylparaben is regulated as a preservative in the European Union under Annex V of the Cosmetics Regulation. The European Commission's SCCS issued a final opinion in December 2023, with a corrigendum adopted in February 2024. The SCCS concluded that Methylparaben could be used as a preservative at concentrations up to 0.4% expressed as acid when used alone; for mixtures of esters, the SCCS opinion addresses use up to 0.4% Methylparaben within a total ester concentration not exceeding 0.8% expressed as acid.
These figures should not be treated as a universal formulation limit for every country or every cosmetic product. Finished-product manufacturers must verify the requirements applicable to their intended market and product category.
Methylparaben should be stored in a well-closed container and protected from contamination and unsuitable environmental conditions. The International Pharmacopoeia specifically recommends storage in a well-closed container.
Suitable packaging should protect the material from:
Storage conditions should always follow the actual product specification and Safety Data Sheet supplied for the commercial material.
Methylparaben is an established cosmetic preservative ingredient belonging to the paraben family. With CAS Number 99-76-3, molecular formula C₈H₈O₃, and molecular weight 152.15 g/mol, it is used in the development of various cosmetic and personal care preservation systems.
Its limited water solubility, crystalline physical form and preservative function are important considerations during formulation development. Finished products should be assessed for preservative performance, formulation compatibility, concentration and applicable regulatory requirements.
| Parameter | Specification |
|---|---|
| Appearance | White or colourless crystals / white powder |