Although there are many types of flame retardants, there are mainly two types of flame retardants in general, and these two types are classified by the method of use. One of these two types is an additive flame retardant, and the other is a reactive flame retardant. The additive flame retardants are divided into organic flame retardants and inorganic flame retardants. Additive flame retardants are flame retardants added to combustible polymers. Reactive flame retardants have flame retardant properties during the combustion process by reacting with combustibles.