Actilight-surface with self-Cleaning properties Two components need to work together to trigger the photocatalytic process of this self-cleaning toilet :the UV light embedded in the lid, and the special zirconium coating with titanium dioxide. The UV light automatically turns on when the sensor-activated lid closes, and breaks down organic substances left in the toilet bowl. The hydrophilic property of the coating helps to thoroughly combat and wash away all dirt from the toilet,keeping it clean for a much longer time.