Thermoplastics are largely comprised of carbon, which makes most plastics inherently flammable. To ensure safety in applications that may be exposed to fire, flame-retardant additives are introduced during processing.

Flame retardants are generally classified as halogenated or non-halogenated, and Hubron can supply masterbatch solutions from either category, available on polyolefin or styrenic carriers.

Halogenated flame retardants, as the name suggests, contain elements from the halogen group – typically bromine or chlorine. These additives act in the gas phase, suppressing flames by reducing the fuel available to the fire. When heated, they release halogen radicals, which disrupt combustion by converting highly reactive free radicals into more stable, non reactive compounds in a process known as quenching. Halogenated flame retardants are highly effective and suitable for use across a wide range of thermoplastics. However, because they release harmful gases when burned, their use is increasingly restricted where non-halogenated alternatives are available.

Non-halogenated flame retardants are typically phosphorus-based. These additives reduce flammability by forming a protective char layer that insulates the plastic from heat and oxygen, limiting the fuel available to the fire. Such char forming systems are referred to as intumescent systems.