This short guide explains the commonly used materials — LSZH and PVC — how industry fire-rating systems (plenum, riser, vertical flame tests) work, and practical tradeoffs so you can pick the right cable for the space and code requirements. The focus here is strictly on fiber cable fire ratings and. FOSC 400 FR fire resistant, fiber optic splice closures are made with a flame retardant material and can be used for splices in cable vaults and buildings. All FOSC 400 closures have an easy-to-use mechanical clamping system for the dometo base seal. Cable ports are sealed with heat shrink tubing. onal during fire. Stagger layers as recommended by cable manufacturer o emove all cable grease. It features IP68 sealing and reinforced plastic construction to resist heat, cold, light, and oxygen exposure.
