Flame resistant polyester monofilament yarn is a synthetic fiber product that has flame retardants added during the spinning process. Phosphate-based flame retardants such as red phosphorus, phosphoric ester, and halogenated phosphoric ester are the most commonly used additives during spinning. The main feature of this product is that it self-extinguishes when ignited, and it is difficult to ignite. The degree of flame resistance depends on the amount of flame retardant added during spinning, but usually does not exceed 16%.