Used primarily as a photoinitiator in UV-curable systems such as inks, coatings, and adhesives. It absorbs ultraviolet light and generates free radicals that initiate polymerization, enabling fast curing under UV exposure. Commonly found in printing inks and protective coatings where low yellowing and good weather resistance are required. Also employed in some cosmetic formulations as a UV absorber to enhance product stability against sunlight degradation.