Chemical strategies for fireproofing porous flammable materials: advances, applications, and environmental considerations

Purpose. This paper provides a comprehensive overview of the chemical strategies used for fireproofing porous flammable materials. It aims to synthesize recent advances, outline key mechanisms of action, and evaluate the environmental and health implications of different flame retardant classes. The work addresses the urgent need for balancing fire safety with sustainability and regulatory compliance. Methods. A systematic review of peer‑reviewed research, standards, and technical reports from 2018 to 2024 was conducted. Data sources included scientific journals, regulatory documents, and industry guidelines. The analysis covered halogenated and halogen‑free flame retardants, nanostructured systems, bio‑based chemicals, and hybrid approaches. Special focus was given to studies employing advanced characterization techniques, cone calorimetry, thermal analysis, and life cycle assessment. Findings. Halogenated flame retardants remain effective but are increasingly restricted due to toxicity and environmental persistence. Halogen‑free alternatives, such as ammonium polyphosphate, aluminum diethyl phosphinate, DOPO derivatives, and bio‑based systems, show promising performance, especially when combined with nanomaterials or reactive chemistries to enhance stability. Innovative solutions, including metal-organic frameworks, graphene derivatives, and phytic acid‑based coatings, are emerging for improved efficacy and lower ecological footprint. However, scalability, cost, and long‑term durability remain challenges. The porosity of materials introduces specific issues such as leaching and off‑gassing, necessitating careful selection and application methods. Regulatory frameworks like REACH and the Stockholm Convention play a decisive role in guiding safer chemical adoption. Application field of research. Developing safer and more sustainable fire protection strategies in the age of advanced materials and growing ecological awareness.