Role of halogen-free fire retardant recycling in enhancing the sustainability of building materials

Fire retardants are widely used in buildings to protect life and property by mitigating fire hazards. Most fire retardants contain halogen elements, but their use is currently restricted to electronic products because of their negative environmental and health impacts. Moreover, although growing fire safety requirements for building materials have strengthened the demand for fire retardants, it is expected that halogen-containing materials will be restricted in various fields in the near future. Therefore, the construction industry and scientific community must develop sustainable halogen-free fire retardants (HFFRs). However, no clear direction for achieving these systems has yet been determined. An overview is provided of HFFR applications in the manufacturing of interior building materials such as wood, polymers, and metals. Recent advancements in the HFFRs for building applications and recycling approaches are discussed. The role of HFFR recycling in enhancing the sustainability of building materials is highlighted. The challenges of the current HFFR recycling methods and directions for addressing these challenges are also discussed. Strategies are proposed for recycling wood, polymers, and metal building materials, highlighting the practical implementation and scalability of these strategies for sustainable building applications. Finally, end-of-life strategies to enhance HFFR sustainability in building materials are proposed, with practical examples of industrial applications in construction, demonstrating the potential of applying these methods. This study aims to drive the development of more sustainable HFFRs, contributing to safer and more sustainable buildings.