Difference between inherent flame retardant and treated fabric

Inherent FR fabrics are made of fibers in which the FR properties are in-inbuilt during the polymerization and can never be worn away or washed out. The actual structure of the fiber itself is non-flammable; therefore, the flame retardant property is permanent.

On the other hand treated FR fabrics are made by applying a flame-retardant chemical finish to a fabric or by adding a chemical treatment to the fibers before they are woven or knitted into the fabric. The chemicals form a strong bond with the polymer chain of fibre that is difficult to remove by washing when the recommended laundering instructions are followed accurately. The chemical treatment alters the molecular structure of the polymer.