Dielectric breakdown voltage is the result of the sudden transition of a portion of the dielectric from an insulating state to a highly conductive state. As Gap Pad is a solid, there will be permanent and chemical changes in Gap Pad from electrical isolating to electrical conductive that cause electrical damage to devices. The Comparative Tracking Index (CTI) is used to measure the electrical breakdown properties of an insulating material such as Gap Pad. The Bergquist Company uses UL as a safety and certification body for ensuring quality industry standards. UL ratings can be found on all Bergquist company Gap Pad products.