Which additives are used to reduce the flammability of polymers?

Flame retardants are specifically formulated additives that enhance the resistance of polymers to ignition and help slow down the spread of flames. These compounds operate by various mechanisms, such as forming a protective char layer on the polymer surface, releasing non-flammable gases that dilute flammable vapors, or creating a thermal barrier to slow down heat transfer. Their primary purpose is to mitigate the fire risks associated with polymers, making them safer for use in a wide range of applications, such as electrical components, textiles, and construction materials.

In contrast, plasticizers are used to increase the flexibility and workability of polymers but do not inherently affect flammability. Fillers are added to improve strength, reduce cost, or modify other properties, and they typically do not provide any flame-retardant characteristics. Colour pigments are employed to give color to the material but also do not influence its flammability. Therefore, flame retardants are the additives that directly reduce the flammability of polymers, making that the correct choice.