Abstract: The present invention relates to a conductive composition for protecting electric connections from parasitic currents, particularly those due to irradiations of X-ray photons. It comprises a silicone elastomer, preferably of the cold-curing type, mixed with a solvent and filled with fine particles of carbon black forming an electrically homogeneous structure after polymerization. Metallic conductors of electrical connections are thus coated with this composition by means of an apparatus comprising a hermetic housing 1 containing the electrical connection 3 to be coated and connected by an at least partially transparent tube 4 to an impregnation tank 5 at whose outlet a tubular furnace 12 is present, a partial vacuum being applied in the housing and the tube. Application to the protection of electrical connections which are exposed to X-rays is shown in FIG. 1.