1,4-Phenylenediphosphonic acid is primarily used as a chelating agent in various industrial processes. It is effective in binding metal ions, making it valuable in water treatment systems to prevent scale formation and corrosion. In the field of material science, it is utilized as a precursor for the synthesis of metal-organic frameworks (MOFs), which have applications in gas storage, separation, and catalysis. Additionally, it is employed in the production of flame retardants, where it enhances the fire resistance of polymers and textiles. Its ability to form stable complexes with metals also makes it useful in the formulation of coatings and adhesives, improving their durability and performance.