Stearic Acid – Cosmetic Uses in Emulsions and Skin Care

What Is Stearic Acid?

Stearic Acid is a naturally occurring fatty acid found in both animal and plant sources. In cosmetic formulations, vegetable-derived Stearic Acid is commonly used.

It forms the basis of many lotions and emulsions and can contribute to the consistency and stability of the formulation. It also helps protect the skin against moisture loss.

Cosmetic Applications

Stearic Acid is widely used in cosmetic formulations for several functions, including:

• Emulsifying
• Emulsion stabilising
• Cleansing
• Refatting
• Skin conditioning

Stearic Acid can also react with triethanolamine or sodium hydroxide to form soap in situ. This can help stabilise an emulsion by supporting the formation of a structured system that reduces separation of the oil and water phases.

Safety

The safety of Stearic Acid, together with Lauric Acid, Myristic Acid, Oleic Acid, and Palmitic Acid, has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The panel concluded that these ingredients are safe for use in cosmetic products.

Stearic Acid is also included by the U.S. Food and Drug Administration (FDA) among direct food additives considered Generally Recognized As Safe (GRAS).

Ingredient Information

INCI Name: Stearic Acid
CAS Number: 57-11-4
EINECS/EC Number: 200-313-4
Functions: Emulsifying, Emulsion Stabilising, Refatting, Cleansing

References

Dweck, Anthony. Handbook of Natural Ingredients (Dweck Books 4). Dweck Data.