A gas blocking cable includes cabled wires, where each wire includes cabled conductors having interstitial areas there between. An insulation material circumferentially surrounds the cabled conductors and a conductor filling material is positioned within the interstitial areas between conductors. A shield circumferentially surrounds the cabled wires so that a cable is formed with areas between the wires. A wire filling material is positioned within the areas between the wires. Each of the conductor filling material and wire filling material is inert, non-flammable and able to withstand a temperature of at least approximately 200° C.