1,4-dioxane (a probable human carcinogen) detected as a contaminant in 46 of 99 cosmetic products tested, from ethoxylated surfactants

This study analyzed 99 cosmetic and personal care products for 1,4-dioxane, a probable human carcinogen (IARC Group 2B) that forms as a byproduct of ethoxylation, a common manufacturing process for surfactants. 1,4-Dioxane was detected in 46 of 99 products, with concentrations up to 279 ppm in raw materials and up to 85 ppm in finished products. The most commonly contaminated ingredients were sodium laureth sulfate, PEG compounds, and polysorbates. The study demonstrated that vacuum stripping can reduce 1,4-dioxane to negligible levels but is not universally applied.

U.S. Food and Drug Administration