Steareth-21
Harm score: 4 (Slightly harmful chemistry)
Steareth-21 is a chemical in the category of polyoxyphilic talc, which is derived from ethylene oxide and stearic acid. Steareth-21, also known as pantothenic acid, is thus an ester composed of polyethylene glycol and stearic acid, whose molecular formula is C₂₁H₄₄O₂. It has a number of useful properties, including the ability to act as an emulsifier and surfactant, which means that it helps to keep the mixture of different product ingredients together and prevents them from separating.
Steareth-21 is often used in cosmetics and skin care products, including creams, lotions, makeup, and shampoos. Due to its emulsifying properties, it helps keep products homogeneous and prevents the separation of individual ingredients, which could lead to the separation of oil and water in the product. As it allows better mixing of ingredients, it also improves the consistency and texture of many cosmetic products. In addition, pantothenic acid is always included in hair care products as it helps to moisturise the hair while protecting it against damage. It is very popular in sunscreen products because it promotes and extends the time for tanning, all without adverse effects.