EN50290‑2‑X contains, in its various parts, the requirements for polymeric insulating, sheathing and covering materials that are used for metallic and optical fibre cables ( Table1). Table1 Materials currently used in metallic and optical fibre communication cables (informative) Standard Application Materials Insulation/Buffer Sheath EN50288 (excluding -7) Multi element metallic cables (data cable) PE, PP, FEP PVC, HFFR-LS, FEP EN50288‑7 Multi element metallic cables (instrument, fieldbus & control cable) PVC, PE, PP, XLPE, PA PVC, HFFR-LS , EN50441 Indoor telecom PVC, PE, PP, PVC, HFFR-LS EN50407 Outdoor telecom PE, PP PE EN50117 Coaxial cables PE, PP, FEP PVC, HFFR-LS , PE, FEP EN60794 Optical fibre cables PVC, PP, PBT, TPE, PA, HFFR-LS PVC, PE, HFFR-LS, TPE The materials to be used for EN standardised communication cables are not, and will not be, restricted only to those defined ( Table1). New materials for cables will be described in further parts of the series. The current structure of the EN50290‑2‑NN series is outlined in AnnexA. Furthermore, the use of materials described in the EN50290‑2‑NN series for other cable applications outside those defined ( Table1) is not prohibited, but it is strongly recommended that expert advice be taken before such use, or before any proposal for incorporation into another standard.