Used as a flame retardant additive in polymers, particularly in polyolefins and engineering plastics. It enhances thermal stability and reduces flammability by promoting char formation during combustion. Its cyclic structure allows for efficient radical trapping in the gas phase, improving fire resistance without compromising mechanical properties. Also employed in coatings and electronic materials where low smoke emission and high ignition resistance are required. Shows compatibility with other phosphorus-based flame retardants for synergistic effects.