Article last updated: October 15, 2024
Aluminum stearates, including aluminum distearate and aluminum tristearate, are compounds derived from the reaction of stearic acid with aluminum salts. Stearic acid is a fatty acid commonly found in animal and vegetable fats, making aluminum stearates a product of both natural and synthetic origins. These compounds are also known by other names such as aluminum octadecanoate and aluminum stearate.
The use of aluminum stearates in cosmetics dates back several decades. Initially, they were employed in industrial applications due to their thickening and stabilizing properties. Over time, their utility in cosmetic formulations became apparent, leading to their widespread adoption in the beauty and personal care industry. Their ability to improve the texture and stability of products made them a valuable ingredient in various formulations.
Aluminum stearates are typically produced through a process called precipitation. In this method, stearic acid is reacted with an aluminum salt, such as aluminum sulfate, in an aqueous solution. The resulting aluminum stearate precipitates out of the solution and is then filtered, washed, and dried to obtain the final product. This process ensures a consistent and high-quality ingredient suitable for use in a wide range of cosmetic products.
In this section, we will delve into the officially recognized cosmetic benefits and uses of Aluminum Stearates:
Aluminum Stearates serve as an anticaking agent, which means they help prevent the clumping of powdered or granulated ingredients. This is particularly useful in products like loose powders, eyeshadows, and dry shampoos, ensuring that the product remains smooth and easy to apply.
As an emulsion stabilizer, Aluminum Stearates help maintain the consistency of emulsions, which are mixtures of oil and water. This is crucial for products like lotions and creams, where a stable emulsion ensures that the product remains effective and pleasant to use over time.
Aluminum Stearates also act as opacifying agents, which means they help make a product less transparent or opaque. This is beneficial in products like foundations and concealers, where a more opaque finish is often desired to provide better coverage.
As an emollient, Aluminum Stearates help to soften and smooth the skin. This makes them a valuable ingredient in moisturizers and other skincare products, providing a more pleasant texture and feel to the skin.
Lastly, Aluminum Stearates are used for viscosity control, meaning they help to thicken or thin a product to achieve the desired consistency. This is important in a wide range of products, from creams to gels, ensuring that they are easy to apply and use.
Note: the listed benefits above are exclusively based on the officially recognized and defined functions of the ingredient, as documented by the International Nomenclature of Cosmetic Ingredients (INCI).
Aluminum stearates, including aluminum distearate and aluminum tristearate, are generally considered safe for use in cosmetics. However, as with any ingredient, there are potential side effects and considerations to keep in mind.
Regarding individuals who are pregnant or breastfeeding, there is a lack of specific data on the topical usage of aluminum stearates during pregnancy and breastfeeding. Therefore, it is advisable to consult a healthcare professional for further advice.
Adverse reactions to aluminum stearates are uncommon, but it is always prudent to perform a patch test before widespread usage to ensure there is no adverse reaction.
In terms of comedogenicity, aluminum stearates have a rating of 2 on a scale of 0 to 5. This means they have a low to moderate potential to clog pores, which could be a concern for individuals prone to acne, blemishes, or breakouts. Those with acne-prone skin should monitor their skin’s response when using products containing this ingredient.
