Used as a reactive flame retardant in polymer manufacturing, particularly in polyurethane foams and epoxy resins. It participates in the polymer backbone, enhancing thermal stability and flame resistance without easily leaching out. Commonly applied in electrical enclosures, construction materials, and automotive components where fire safety is critical. Its anhydride functionality allows it to react with hydroxyl or amine groups, making it suitable for use in coatings and adhesives that require improved fire performance.