Used as a light stabilizer in polymers, especially in polypropylene, polyethylene, and other plastics exposed to UV radiation. It prevents degradation caused by sunlight, helping to maintain color, strength, and flexibility over time. Commonly added during processing of films, fibers, and molded parts for outdoor applications like automotive components, agricultural films, and construction materials. Also used in coatings and adhesives where long-term weatherability is required. Works synergistically with antioxidants to enhance overall durability.