Ethylparaben (Ethyl 4-hydroxybenzoate) - CAS 120-47-8
Ethyl 4-Hydroxybenzoate (Ethylparaben, CAS 120-47-8): Overview
1. Introduction
Ethyl 4-hydroxybenzoate (Ethylparaben) is an ester of para-hydroxybenzoic acid widely used as a preservative. Its internationally recognized CAS number is 120-47-8. It belongs to the paraben group (along with methylparaben and propylparaben) and is designated as E214 when used in the food industry. Ethylparaben exhibits pronounced antimicrobial activity against bacteria and fungi.
2. Chemical Structure and Physicochemical Characteristics
Structure: Chemical formula C₉H₁₀O₃. The molecule consists of a benzene ring with hydroxyl and ethyl ester groups positioned para to each other.
Physical properties: Melting point approximately 115–118°C. Solubility: readily soluble in alcohols, moderately soluble in water. This allows Ethylparaben to be easily incorporated into cosmetic and pharmaceutical formulations.
Stability: Maintains preservative properties across a wide pH and temperature range; resistant to hydrolysis under weakly acidic and neutral conditions. In alkaline media, gradual hydrolysis may occur, leading to reduced efficacy.
3. Mechanism of Antimicrobial Action
Ethylparaben, like other parabens, disrupts the functions of microbial cell membranes. It is believed that parabens inhibit key enzymatic processes and membrane permeability, preventing the growth and reproduction of pathogenic bacteria, molds, and yeasts.
4. Main Areas of Application
Pharmaceuticals: Used in ointments, creams, syrups, and other dosage forms to protect against microbial spoilage.
Cosmetics: Included in shampoos, lotions, and creams to prevent mold and bacterial growth in emulsion systems or solutions.
Food industry (E214): May be added to certain food products and beverages to extend shelf life, regulated at levels established by local and international legislation.
5. Safety and Regulations
Toxicological profile: At recommended concentrations, Ethylparaben is considered safe. However, some individuals may experience allergic reactions (contact dermatitis).
Regulatory requirements: Maximum permitted levels of parabens in cosmetics and food are established in the European Union and many other countries.
Compatibility: Potential interactions with other formulation components, especially at high pH levels or in the presence of surfactants, should be considered.
6. Conclusion
Ethyl 4-hydroxybenzoate (CAS 120-47-8) provides effective protection of products against microorganisms. Its relatively low cost, stability, and broad spectrum of action make it widely used in the food, cosmetic, and pharmaceutical industries. At the same time, it is necessary to control dosages and consider possible individual intolerance in some users.