Sodium Stearate[2]

Updated: 2026-09-12

Overview

Sodium Stearate is a sodium salt of stearic acid, widely recognized for its emulsifying and stabilizing properties. It is a key ingredient in various industrial and consumer products, particularly in the cosmetics, pharmaceutical, and food sectors. Its ability to form stable emulsions makes it invaluable in formulations requiring uniform mixtures of oil and water. Historically, Sodium Stearate has been used since the 19th century, primarily in soap manufacturing. Today, its applications have expanded to include personal care products, lubricants, and even some plastic stabilizers. The compound is synthesized through the saponification of stearic acid with sodium hydroxide, resulting in a versatile and cost-effective chemical.

Physical and Chemical Properties

Sodium Stearate appears as a white, waxy solid or powder with a slight fatty odor. It has a melting point range of 245-270°C, where it decomposes rather than boiling. The compound is highly soluble in hot water and alcohol but poorly soluble in cold water, which affects its application methods. Its molecular structure includes a long hydrophobic tail and a hydrophilic head, making it an effective surfactant. This amphiphilic nature allows Sodium Stearate to reduce surface tension between oil and water, facilitating emulsion formation. Additionally, it exhibits mild alkaline properties due to its sodium content, which can influence pH-sensitive formulations.

Main Applications

In the cosmetics industry, Sodium Stearate serves as a thickener and stabilizer in creams, lotions, and makeup products. Its emulsifying properties ensure smooth textures and prolonged shelf life. The pharmaceutical sector utilizes it in tablet formulations and ointments to improve consistency and drug delivery. The food industry employs Sodium Stearate as an anti-caking agent and emulsifier, particularly in powdered products and processed foods. It is also a common ingredient in soaps and detergents, where it enhances cleaning efficiency by breaking down oils and grease. Industrial applications include its use as a mold release agent and in the production of certain plastics and rubber products.

Safety and Storage

Sodium Stearate is generally regarded as safe for use in regulated quantities. However, direct contact with eyes or skin may cause irritation, necessitating protective equipment like gloves and goggles during handling. Inhalation of dust should be avoided to prevent respiratory discomfort. Proper storage involves keeping the compound in a cool, dry environment, sealed tightly to prevent moisture absorption. It should be stored away from strong acids and oxidizers to avoid hazardous reactions. Bulk storage in industrial settings requires compliance with local chemical storage regulations to ensure safety and stability.

B2B Procurement Guide

When procuring Sodium Stearate, buyers should specify the required grade—industrial, food, or pharmaceutical—based on application needs. Food and pharmaceutical grades must meet stringent purity standards, often requiring certifications like USP or FCC. Industrial-grade variants are more cost-effective but may contain impurities unsuitable for sensitive uses. Suppliers typically offer Sodium Stearate in 25 kg bags or bulk containers. Pricing varies with purity, order volume, and market conditions, averaging $2-$5 per kg. Buyers are advised to request samples for quality testing and verify supplier reliability through industry references or certifications. Long-term contracts can secure stable pricing and supply consistency.