Used primarily as a photoinitiator in UV-curable formulations such as inks, coatings, and adhesives. It absorbs ultraviolet light to generate free radicals, initiating rapid polymerization of monomers and oligomers. Commonly found in printing inks, dental composites, and electronic encapsulants due to its efficiency and low yellowing tendency. Also employed in 3D printing resins where controlled curing is essential. Its reactivity can be enhanced when used with co-initiators like tertiary amines.