Stearic Acid

What is it?

Stearic acid is a saturated fatty acid, a waxy solid. Stearic acid is one of the most common saturated fatty acids found in nature, following palmitic acid. Although the ingredient name is ‘stearic acid’, the material is often a blend of both stearic and palmitic acids. It is only slightly soluble in water, but it easily dissolves in oil.

What does it do?

This ingredient provides emulsification properties to the formula, keeping the oil and water components from separating (like salad dressing).

Stearic acid is widely used in soaps and cosmetics, candles, plastics and paints.

How is it made?

Our Stewardship Model guides us to select ingredients which have been processed in a manner that supports our philosophy of human and environmental health.

Though stearic acid occurs naturally in vegetable and animal fats, it requires some processing to isolate it in purified form to be used as an ingredient. Tom’s uses a vegetable derived stearic acid from palm kernel oil, sourced only from suppliers who are member of RSPO (Roundtable on Sustainable Palm Oil).

The palm kernel oil is partially crystallized to separate it into liquid and solid fractions. The solid fraction of the palm kernel oil (also known as palm stearin) undergoes hydrogenation to further saturate the material. Hydrogenation is a process in which liquid vegetable oils are converted to solid or semi-solid fats.

The hydrogenated palm stearin (triglycerides) is split by applying heat with added water and steam (above 200 °C) to separate the fatty acids from the glycerin backbone.  The resulting fatty acid mixture is then distilled and separated to isolate the stearic and palmitic fractions.

What are the alternatives?

Stearic acid can be derived from rendered fat of farm and domestic animals—the stearic acid in Tom’s of Maine products comes from RSPO-certified palm kernel oil and is not of animal origin.

There are other emulsifiers on the market which would not meet our strict Stewardship guidelines.

Is this the right option for me?

Stearic acid, whether plant or animal derived, has been used in personal care products extensively for many years.  Stearic Acid is considered to be Generally Recognized as Safe by the US FDA.1

Tom’s of Maine recognizes that no two people are alike, and even with naturally derived ingredients, some individuals may develop an allergic reaction that is unique to them. As with any product, be sure to discontinue use if you experience discomfort or other indications that the product may not be appropriate for your individual body chemistry.

1 21CFR 184.1090