Octocrylene is an organic compound used as an ingredient in sunscreens and cosmetics. It is an ester formed by the condensation of a diphenylcyanoacrylate with 2-ethylhexanol. It is a viscous, oily liquid that is clear and colorless.
The extended conjugation of the acrylate portion of the molecule absorbs ultraviolet light, protecting the skin from direct DNA damage. The ethylhexanol portion is a fatty alcohol, adding emollient and oil-like (water resistant) properties.
This organic compound can penetrate into the skin where it acts as a photosensitizer. This results in an increased production of free radicals under illumination. Free radicals are known to induce indirect DNA damage and an increased concentration of free radicals might have contributed to the increased incidence of malignant melanoma in sunscreen-users compared to non-users (see Epidemiologie of malignant melanoma)