Ammonium polyphosphate is widely used as a flame retardant in various materials, including plastics, textiles, and coatings. It works by promoting the formation of a protective char layer when exposed to heat, which helps to prevent the spread of flames. In agriculture, it serves as a highly effective fertilizer, providing a slow-release source of phosphorus and nitrogen, essential nutrients for plant growth. Additionally, it is utilized in the production of intumescent paints and fireproofing agents, where it expands when heated to form an insulating barrier. Its versatility and effectiveness make it a valuable component in both industrial and agricultural applications.