Fire treatment of wood is moving towards PIN FR solutions, with challenges being effects on mechanical properties, FR leaching and water uptake. This short overview paper, intended for the Wood a Fire Safety Conference 2020 (Slovakia, postponed to 1-4 November 2020) outlines the fire chemistry of wood, flame retardant modes of action (in particular accentuation of natural char formation, e.g. by ceramification or dehydration) and summarises different FR families used, either by surface coating or impregnation. Today, most FR treatments are PIN (non-halogenated) with a move away from boron salts because of toxicity questions and low leaching resistance. Developing solutions are based on nitrogen, phosphorus, mineral hydroxides and carbonates or silicates.
“Fire Retardant Treatment of Wood – State of the Art and Future Perspectives”, P. Sauerbier et al., International Scientific Conference on Woods & Fire Safety WFS 2020: Wood & Fire Safety pp 97-102 https://doi.org/10.1007/978-3-030-41235-7_14