Ammonium polyphosphate is widely used as a flame retardant in various materials, including plastics, textiles, coatings, foams, paper, and construction materials. It works by promoting the formation of a protective char layer when exposed to heat, which helps to prevent the spread of flames and enhances safety in buildings.

In agriculture, it serves as a highly effective fertilizer, providing a slow-release source of phosphorus and nitrogen, essential nutrients for plant growth. Its water-soluble nature ensures that nutrients are gradually available to plants, reducing the risk of leaching and improving soil fertility.

Additionally, it is utilized in the production of intumescent paints and fireproofing materials, where it acts as a key component in expanding coatings that protect structural elements from fire damage. It is also employed as an additive in paints and coatings to improve heat and fire resistance, and in the paper and textile industries to enhance fire-retardant properties.

Furthermore, it is used in the production of dry powder fire extinguishing agents effective for class A, B, and C fires.

Its versatility and effectiveness make it a valuable specialty chemical in both industrial and agricultural applications.