What it is
Trideceth-6 is an ethoxylated fatty alcohol, made by reacting tridecyl alcohol with about six units of ethylene oxide. The number 6 indicates the average degree of ethoxylation, which influences its water solubility and emulsifying behavior. In sunscreens and other leave-on or rinse-off products it helps blend oil and water phases, dissolve poorly soluble ingredients, and stabilize emulsions.
Safety & warnings
Trideceth-6 is generally well tolerated in cosmetic use. As with other ethoxylated (PEG-type) surfactants, manufacturing controls are used to limit residual ethylene oxide and 1,4-dioxane impurities. It is not considered a notable allergen or comedogen at typical use levels.
Origin & sourcing
Synthetic; produced by ethoxylation of tridecyl alcohol, which may itself be of petrochemical or vegetable origin.
Questions everyone asks
What does Trideceth-6 do in sunscreen?
It acts as a surfactant and emulsifier, helping mix the oil and water phases and dissolve ingredients that do not readily dissolve in water.
What does the number 6 mean?
It is the average number of ethylene oxide units added per molecule, which affects how water-soluble and how strong an emulsifier the ingredient is.