OFNP/OFCP is the highest flame-retardant rating in the NEC standards, meaning it is plenum-grade. If a fan forces airflow onto a bundle of such cables, the flames will self-extinguish within five metres, without any resultant toxic or corrosive gases being emitted. Below are the most commonly used fiber optic cable jacket materials and their key characteristics: Excellent moisture, abrasion, and corrosion resistance; good electrical and chemical stability; HDPE is harder and heat-resistant; LDPE is more flexible. Low cost, flexible. In the National Electrical Code (NEC), fiber optic cables are categorized into various fire ratings, including OFNP/OFCP, OFNR/OFCR, OFNG/OFCG, and OFN/OFC. To ensure compliance to these requirements, a. Optical Fiber Nonconductive Plenum (OFNP) and Optical Fiber Nonconductive Riser (OFNR) are two fire resistance ratings used for fiber optic cables. Before we can talk about the flame retardant grade, we can first understand what is LSZH (Low Smoke Zero Halogen). Color coded for easy termination. For “X” in part number, see optical characteristics chart For X in Part Number use. Plenum MECHANICAL, ENVIRONMENTAL & FLAME CHARACTERISTICS: Crush Resistance EIA-455-41.