Stearic acid

Stearic acid (CAS 57-11-4) is a saturated long-chain fatty acid derived primarily from animal fats and vegetable oils. FEMA 3035.

Where is Stearic acid used?

• Plastics and rubber: internal lubricant and mold release agent that reduces friction during compounding
• Personal care: primary emulsifier and thickener in creams, lotions and bar soaps
• Metalworking and lubricants: greases, drawing compounds and wire-pulling lubricants that reduce tool wear
• Textile and leather processing: softening and finishing agent during fabric treatment
• It functions as a lubricant, emulsifier and processing aid in manufacturing.
• Used in waxes.
• Commonly used in fireworks as a coating for metal powders.
• Processed into metal soaps and additives for the plastics industry.
• Acts as an emollient in skin care products, forming a protective barrier and reducing moisture loss.

Formulation notes

• In leave-on cosmetic products, typically used at 1 to 10%.
• In candle making, recommended at about 10% of the total raw material weight.
• In emulsions, used at 1–8%.

Typical specification

• Commercial stearic acid typically contains about 50% stearic acid, 45% palmitic acid, and 5% oleic acid, though proportions can vary.
• Commercial stearic acid typically has an acid value of 195 to 211 mg KOH/g.
• Triple-pressed stearic acid grades have an iodine value below 4.
• Double-pressed stearic acid has a titer of 54 to 57°C.
• Available in flakes, off-white form.

Regulatory status

• Has the tariff code 29157050.
• RAL-compliant and RSPO MB products are offered.

Storage, packaging and handling

• Should be stored in a cool, dry place away from sunlight.

Frequently asked questions about Stearic acid

Can stearic acid be used as the sole emulsifier in a formulation?

No, stearic acid is not an emulsifier on its own; it is generally used together with other emulsifiers.

How does animal-based stearic acid differ in composition from other grades?

Stearic acid based on animal raw materials has a C-16 content of 25–35%.

What functions does stearic acid provide in emulsions and surfactant systems?

It adds consistency, stability and opacity to emulsions, and is used as an opacifier in shampoos and shower gels.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.