What it is
Tridecyl trimellitate is a large, branched synthetic ester that imparts a smooth, cushioned, non-greasy feel to formulations. It is used as an emollient and texture modifier and can help suspend pigments and improve the spreadability of products such as sunscreens and color cosmetics. Its high molecular weight gives a substantive, long-lasting skin feel.
Safety & warnings
Generally well tolerated and used as a skin-feel emollient. As a heavy ester it may feel rich on very oily or acne-prone skin, though it is widely used in lightweight cosmetic textures. It is not a recognized fragrance allergen.
Origin & sourcing
Synthetic; produced by esterifying trimellitic acid with tridecyl alcohol.
Questions everyone asks
What does tridecyl trimellitate do in a sunscreen?
It acts as an emollient and texture agent, giving a smooth feel and helping disperse pigments; it is not a UV filter.
Is it natural or synthetic?
It is a synthetic ester made by combining tridecyl alcohol with trimellitic acid.