Benzophenone

"Benzophenone is the organic compound with the formula (C₆H₅)₂CO, generally abbreviated Ph₂CO. Benzophenone is a widely used building block in organic chemistry, being the parent diarylketone."

"Benzophenone can be used as a photo initiator in UV-curing applications such as inks, imaging, and clear coatings in the printing industry. Benzophenone prevents ultraviolet (UV) light from damaging scents and colors in products such as perfumes and soaps. It can also be added to the plastic packaging as a UV blocker. Its use allows manufacturers to package the product in clear glass or plastic. Without it, opaque or dark packaging would be required."

"In biological applications, benzophenones have been used extensively as photophysical probes to identify and map peptide–protein interactions."