Dan Masakowski notes the overall trend towards zero halogen, low smoke cables, in many applications, although this is moving faster in Europe than in the USA. A key driver in this trend is the low corrosivity of smoke emitted in fires, both because of the impact on people (preventing escape) and the impact on electrical safety and communications systems. Overall, low combustibility remains however more important than smoke emissions: carbon monoxide emissions are above all related to the quantities of materials burning. Cable trends include moves to cheaper polymers, such as cross linked polyethylene, but the flame retardant systems are similar to conventional cross linked ethyl propyl rubber. A challenge for PIN flame retardant solutions is that intumescents do not function in cross linked polymers, which are increasingly used in cables. Future solutions may include developing higher performance thermoplastics, and using fire protective coatings over the whole cable tray to reduce requirements applicable to the cable materials themselves.
Marmon Innovation was established eight years ago, to provide R&D support for the Marmon Engineered Wire & Cable group (a Berkshire Hathaway company), which as 15 wire and cable companies worldwide, providing basic research and support to the companies on product development. Marmon Innovation has a platform specialised in zero halogen materials. https://marmonewc.com/innovation/