Most thermoplastics are flammable, burning easily when heated to a high enough temperature. Plastics being hydrocarbons, combust through a process with heat which causes pyrolysis and breaks down the long-chain structure into volatile hydrocarbons, hydrogen and hydroxyl-free radicals. These elements formed during combustion are high in energy and react with oxygen, releasing heat and causing fire to spread.

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Flame retardants are added to halogen-free flame retardant formulations in cables to increase resistance to ignition, reduce flame spread, suppress smoke formation and prevent the polymer from dripping. The primary goal is to delay the ignition and burning of materials, allowing people more time to escape the affected area.