Introduction:
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 UVB and short-wave UVA (ultraviolet) rays with wavelengths from 280 to 320nm, 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 Epidemiology of malignant melanoma)[weaselwords]. The only evidence gathered to date of a relationship between sunscreen use and malignant melanoma is correlational, but has not established a causal relationship.

Application:
Used as uv absorbent in plastics, paints and dyes