Sunscreen chemical. Computer graphic of a molecule of the sunscreen chemical 2-ethylhexyl trans-4- methoxycinnamate (C18.H26.O3). The atoms (spheres) of the molecule are colour-coded: carbon (green), hydrogen (yellow) and oxygen (blue). Conjugation (regular spacing of double bonds) is present in this molecule, which means that it is good at absorbing part of the damaging ultraviolet (UV) radiation in sunlight.