A polymer composition formed by: I) fluoropolymers selected from one or more of the following: copolymers based on ethylene, TFE and/or CTFE modified with hydrogenated monomers, or blends of these fluoropolymers with PCTFE; said fluoropolymers and/or the corresponding blends optionally mixed with hydrogenated plasticizers; II) one or more inorganic fire-retardants, treated and not with dispersing agents; III) one or more crosslinking agents; IV) optional additives.