Bisoctrizole is an absorber of UVA and UVB radiation used in sunscreen. Bisoctrizole, or methylene bis-benzotriazolyl tetramethylbutylphenol, is a broad-spectrum organic UV filter that is marketed as Tinosorb M 1. It is a benzotriazole-based organic compound that absorbs, reflects, and scatters both UV-A and UV-B rays.