Ammonium polyphosphate (KYLIN APP201) is a non-halogen flame retardant. It acts as flame retardant by intumescence mechanism. When APP-II is exposed to fire or heat, it decomposes to polymeric phosphate acid and ammonia. The polyphosphoric acid reacts with hydroxyl groups to form a nonstable phosphateester.

Ammonium Polyphosphate coated by Silane (KYLIN APP203) is a flame retardant based on phosphorus /nitrogen synergism,it is coated by Silane based on KYLIN APP201 with special method.