?Octabenzone , its cas register number is 1843-05-6. It also can be called?Ultraviolet Absorber UV-531 ; 2-Hydroxy-4-n-octoxybenzophenone ; 2-Hydroxy-4-n-octyloxybenzophenone ; 2'-Hydroxy-4'-n-octyloxybenzophenone ; 2-Hydroxy-4-(octyloxy)benzophenone ; [2-Hhydroxy-4-(octyloxy)phenyl]phenylmethanone .It is a?is a UV absorber/screener.