Propyl Gallate

Propyl gallate is an ester of the antioxidant gallic acid. Just like that acid, it functions as an antioxidant and helps protect the fats and oils used in cosmetics from becoming rancid. As a raw material, propyl gallate appears as a white to beige crystalline powder.

In 2007, the Cosmetic Ingredient Review Expert Panel recommended limiting propyl gallate to 0.1% in cosmetic formulations, due to potential sensitization issues at higher concentrations. Reports show the vast majority of cosmetic formulations do indeed use propyl gallate in 0.1% or less. Interestingly, propyl gallate is also used an additive to prevent lipid oxidation in foods.