Hydroxyacetophenone

Hydroxyacetophenone is a synthetic antioxidant and skin-conditioning ingredient. The specific antioxidant compound is actually known as p-hydroxyacetophenone, a phenolic antioxidant capable of neutralizing several different types of free radicals. Its secondary benefit is boosting the preservation system in cosmetics. This is advantageous because it allows cosmetic chemists to use a lower amount of preservatives (such as phenoxyethanol) without losing efficacy while at the same time reducing the risk of an allergic reaction.

Even better, hydroxyacetophenone is stable across a wide pH range and types of emulsions, giving it great versatility. Usage levels of hydroxyacetophenone in skin care and cosmetics range from 0.00068%–5%, with a 0.5% concentration being recommended if the goal is to improve preservative efficacy while using a lower amount of the preservative(s). The lower amounts exhibit excellent soothing properties, so in essence this ingredient can also improve skin's tolerance of standard cosmetic preservatives.

The independent Cosmetic Ingredient Review panel has ruled hydroxyacetophenone is safe, indicating that it's not considered irritating or sensitizing when amounts typically used in cosmetics are applied to skin.