Green Flame Retardants for Cellulosic and Polymeric Textile Fibers: Mechanisms, Sustainability, and Future Directions

The inherent flammability of cellulosic and polymeric materials limits their safe applications in textiles, composites, and other industrial products. The growing concern about the environmental and health hazards associated with traditional flame retardants has spurred research into sustainable alternatives. Traditional flame retardants, including phosphorus, halogens, nanomaterials, and intumescent-based systems, have demonstrated significant efficiency in reducing flammability through mechanisms such as radical scavenging, char formation, and thermal shielding. However, their persistence, potential toxicity, and adverse environmental effects have raised regulatory and safety concerns. This review highlights the mechanisms, advantages, and limitations of these traditional flame-retardant systems and emphasizes the need for transitioning toward green flame retardants (FRs) for cellulose and polymeric substrates. Furthermore, the sustainability perspective, economic feasibility, and practical applicability of bio-based FRs were observed through alignment with the United Nations Sustainable Development Goals (SDGs) and a structured strengths, weaknesses, opportunities, and threats (SWOT) analysis. Future research directions are proposed to improve durability, performance consistency, and large-scale implementation of green FRs.