What it is
Cetyl Hydroxyethylcellulose is a nonionic cellulose ether in which long-chain cetyl (C16) groups are grafted onto a hydroxyethylcellulose backbone. The hydrophobic cetyl groups associate in water to build viscosity and stabilize emulsions, so the ingredient is often used to thicken aqueous systems and improve the texture and stability of lotions and creams, including sunscreen formulas. It contributes a smooth, cushiony feel and can form a light film on the skin.
Safety & warnings
Cellulose-based thickeners of this type are generally well tolerated and are considered low risk for irritation. As a high-molecular-weight polymer, it is not expected to penetrate skin meaningfully. It is not a recognized sensitizer or a notable comedogenic ingredient.
Origin & sourcing
Semi-synthetic. It is made by chemically modifying cellulose, a natural plant-derived polysaccharide, first with ethylene oxide to form hydroxyethylcellulose and then with a cetyl-bearing reagent to attach the hydrophobic side chains.
Questions everyone asks
What does Cetyl Hydroxyethylcellulose do in a sunscreen?
It thickens the water phase and helps stabilize the emulsion, giving the product a smoother texture and more consistent, even spread.
Is Cetyl Hydroxyethylcellulose natural or synthetic?
It is semi-synthetic: a naturally derived cellulose backbone that is chemically modified with hydroxyethyl and cetyl groups.