Octocrylene. Computer graphic of a molecule of the sunscreen chemical octocrylene (C24.H27.N.O2). The atoms (spheres) of the molecule are colour-coded: carbon (yellow), hydrogen (white), oxygen (red) and nitrogen (blue). The conjugation (regular spacing of double bonds) found in this molecule means it is good at absorbing part of the damaging ultraviolet (UV) radiation in sunlight.