Dehydroacetic Acid

Dehydroacetic acid is a preservative used in place of older ones like parabens, and its skin record is clean. The Cosmetic Ingredient Review panel, on a fresh look in 2024, kept its long-standing conclusion that the ingredient and its sodium salt are safe as used, finding them non-irritating and non-sensitizing across the clinical tests on file, at the levels cosmetics use, which reach about half a percent. Europe permits it as a preservative up to 0.6 percent and keeps it out of sprays. The open questions sit on the food side, at the doses of eating it rather than the trace in a lotion. A 90-day feeding study in rats set its point of departure on body-weight loss at higher intakes and found no reproductive harm, with a rise in thyroid hormone that reversed once dosing stopped. On the strength of those food-safety questions, not any skin finding, China's 2024 food-additive standard dropped it from butter, bread, pastries, and juices and cut the amount allowed in pickled vegetables. For a product at the concentrations used on skin, the exposure is small and the skin evidence is clean, so the food-additive debate does not carry across to topical use.