The core function of the U120BP anti-fouling glass insulator is to prevent "pollution flashover": During foggy or light rainy weather, contamination layers such as industrial dust and salt particles become moistened and form a conductive path on the insulator's surface. This can cause the high-voltage current to break down the air and generate intense arcing — an event known as a "pollution flashover" accident. The U120BSP significantly increases the creepage distance (i.e., the length of the leakage path for current along the surface), making it much more difficult for a continuous conductive channel to form on the insulator surface under high humidity conditions. As a result, it greatly enhances operational safety in harsh weather environments.