Inorganic Flame Retardants and Mineral Compounds
T.S. Motsoeneng, S. Khumalo, S.M. Mohomane, T.C. Mokhena
Flame- or fire-retardant materials are crucial and valuable when enhancing the flame-retardant properties of materials or compositions that are prone to fire and/or easily combustible. Due to their nature, flame retardants are available in various forms and compositions spanning from organic to inorganic compounds. These compounds can be used individually or in combination as hybrid materials to enhance the flame-retardancy of other materials that are physically and chemically susceptible to fire. When used as hybrid materials, these materials exhibit significantly improved flame-retardant properties. Flame-retardants are widely used in various fields to enhance fire resistance across a broad range of materials and applications. Fire-resistant materials are primarily used in synthetic and/or natural polymers to produce composites with enhanced flame resistance. There is a plethora of characterisation techniques and tests that can be used to determine the fire-resistance properties of a composition incorporating a fire-retardant material. This chapter covers various aspects of flame-resistant materials, including their chemical and physical properties, recent industrial applications, and testing methodologies.
Keywords
Fire Retardants, Endothermic Decomposition, Inorganic Retardants, Mineral Fillers, Layered Silicates, Flammability
Published online 5/1/2026, 14 pages
Citation: T.S. Motsoeneng, S. Khumalo, S.M. Mohomane, T.C. Mokhena, Inorganic Flame Retardants and Mineral Compounds, Materials Research Foundations, Vol. 190, pp 360-373, 2026
DOI: https://doi.org/10.21741/9781644904077-13
Part of the book on Flame Retardant Materials
References
[1] C.A. Wilkie, A.R. Horrocks, P. Hornsby, Chapter 6 – Flame retardant fillers, in fire retardancy of polymeric materials, in: A.B. Morgan and C.A. Wilkie (Eds.), Fire retardancy of polymeric materials, Taylor & Francis, 2024, pp.97-115. https://doi.org/10.1201/9781003380689-6
[2] T. Nazrun, M.K. Hassan, M.R. Hasnat, M.D. Hossain, B. Ahmed, S. Saha, A comprehensive review on intumescent coatings: formulation, manufacturing methods, research development, and issues, Fire 8 (2025) 1-39. https://doi.org/10.3390/fire8040155
[3] R. Gao, H. Ye, J. Chen, S. Chen, X. Fang, M. Zhou, Q. Xue, J. Chai, B. Xing, N. Chen, Recent advances in layered nanomaterial‐based flame retardants for polymer composites, J. Appl. Polym. Sci. (2025) 1-18. https://doi.org/10.1002/app.58069
[4] M.K. Singh, S.M. Rangappa, M. Misra, A.K. Mohanty, S. Siengchin, Recent advancements in nanostructured flame-retardants: Types, mechanisms, and applications in polymer composites, J. Nanostruct. 42 (2025) 101-468. https://doi.org/10.1016/j.nanoso.2025.101468
[5] A.l. Mosawi, Flame retardants, their beginning, types, and environmental impact: a review, JSBCM 74 (2022) 2-8. https://doi.org/10.14382/epitoanyag-jsbcm.2022.1
[6] Y. Hu, Y. Ye, J. Wang, T. Zhang, S. Jiang, X. Han, Functionalization of chitosan and its application in flame retardant: a review, Int. J. Biol. Macromol. 295 (2025) 1-25. https://doi.org/10.1016/j.ijbiomac.2025.139615
[7] R. Gupta, M.K. Singh, S.M. Rangappa, S. Siengchin, H.N. Dhakal, S. Zafar, 2024. Recent progress in additive inorganic flame retardant polymer composites: Degradation mechanisms, modeling, and applications, Heliyon 10 (2024) 1-23. https://doi.org/10.1016/j.heliyon.2024.e39662
[8] M.M.S. Mohd Sabee, Z. Itam, S. Beddu, N.M. Zahari, N.L. Mohd Kamal, D. Mohamad, N.A. Zulkepli, M.D. Shafiq, Z.A. Abdul Hamid, Flame retardant coatings: additives, binders, and fillers, Polym. 14 (2022) 1-23. https://doi.org/10.3390/polym14142911
[9] R. Giri, L. Nayak, M. Rahaman, Flame and fire retardancy of polymer-based composites, Mater. Res. Innov. 25 (2021) 104-132. https://doi.org/10.1080/14328917.2020.1728073
[10] M. Liu, J. Qiao, X. Zhang, Z. Guo, X. Liu, F. Lin, M. Yang, J. Fan, X. Wu, Z. Huang, Flame retardant strategies and applications of organic phase change materials: a review, Adv. Funct. Mater. 35 (2025) 2412492. https://doi.org/10.1002/adfm.202412492
[11] A.J. Andrew, M. Sain, S. Ramakrishna, M. Jawaid, H.N. Dhakal, Environmentally friendly fire retardant natural fibre composites: a review, Int. Mater. Rev. 69 (2024) 267-308. https://doi.org/10.1177/09506608241266302
[12] M.N.A.M. Taib, P. Antov, V. Savov, W. Fatriasari, E.W. Madyaratri, R. Wirawan, L.M. Osvaldová, L.S. Hua, M.A.A. Ghani, S.S.A.O. Al Edrus, L.W. Chen, Current progress of biopolymer-based flame retardant, Polym. Degrad. Stab. 205 (2022) 1-28. https://doi.org/10.1016/j.polymdegradstab.2022.110153
[13] J. Rodrigues, N.G. Shimpi, Nanostructured flame retardants: an overview, J. Nanostruct. 39 (2024) 1-14. https://doi.org/10.1016/j.nanoso.2024.101253
[14] T. Maake, J.K. Asante, W. Mhike, B. Mwakikunga, Fire-retardant wood polymer composite to be used as building materials for South African formal and informal dwellings-a review, Fire 8 (2025) 1-30. https://doi.org/10.3390/fire8020081
[15] T. Kashiwagi, Polymer combustion and flammability-role of the condensed
phase, Symp. (Int.) Combust. 25 (1994) 1423-1437. https://doi.org/10.1016/S0082-0784(06)80786-1
[16] R. Fatima, S. Naseer, M.R.H.S. Gilani, M. Aamir, J. Akhtar, chapter 3 – Metal hydroxides, in: Inamuddin, T. Altalhi, S.A. Mohammed (Eds.), Sustainable materials for electrochemical capacitors, Wiley, 2023, pp.33-64. https://doi.org/10.1002/9781394167104.ch3
[17] P. Selvam, P. Saravanan, S. Palanisamy, L. Umate, R. Saminathan, Improving insulation performance with woven flax/PP hybrid composite reinforced by synthetic alumina and aluminium trihydrate, Interactions 245 (2024) 1-16. https://doi.org/10.1007/s10751-024-02121-7
[18] A. Bîrcă, O. Gherasim, V. Grumezescu, A.M. Grumezescu, Chapter 1 – Introduction to thermoplastic and thermosetting polymers, in: V. Grumezescu, A.M. Grumezescu (Eds.), Materials for biomedical engineering, Elsevier, 2019, pp.1-28. https://doi.org/10.1016/B978-0-12-816874-5.00001-3
[19] P.J. Anderson, R.F. Horlock, Thermal decomposition of magnesium hydroxide, Trans. Faraday Soc. 58 (1962) 1993-2004. https://doi.org/10.1039/tf9625801993
[20] Q. Chen, S. Xu, R. Li, B. Sun, H. Fang, Q. Zhang, Synthesis of highly dispersed magnesium hydroxide and its application in flame-retardant EVA composites, RSC Adv. 15 (2025) 12854-12865. https://doi.org/10.1039/D5RA01067E
[21] S. Kodani, S. Iwasaki, L. Favergeon, N. Koga, Revealing the effect of water vapor pressure on the kinetics of thermal decomposition of magnesium hydroxide, Phys. Chem. Chem. Phys. 22 (2020) 13637-13649. https://doi.org/10.1039/D0CP00446D
[22] Z. Zhou, H. Yu, G. Wang, M. Li, K. Shi, High antimony resistance strain Enterobacter sp. Z1 mediates biomineralization of antimony trioxide, Environ. Int. 195 (2025) 1-11. https://doi.org/10.1016/j.envint.2024.109237
[23] Y. Hu, Y. Zhang, Mechanisms and modes of action in flame retardancy of polymers, in: Y. Hu, X. Wang (1st Ed.), Flame Retardant Polymer Materials, Taylor & Francis, 2019, pp.13-34. https://doi.org/10.1201/b22345-2
[24] M. Kılınç, Production and characterization of boron-based additives and the effect of flame retardant additives on pet-based composites, Middle East Technical University (Turkey), Thesis (2009).
[25] M.J. Rozo, S. Sunder, W. Tabaka, B. Klaffke, H. Ruckdaeschel, B. Schartel, Unveiling aluminum diethyl phosphinate’s dual identity: transfer from epoxy resins to glass fiber-reinforced composites, Polym. Compos. 46 (2025) 12981-12999. https://doi.org/10.1002/pc.29911
[26] X. Hui, D. Fang, G. Wang, F. Ran, X. Zhang, Z. Fu, O. Ruzimuradov, The flame retardant and smoke suppressant effect of transition metal hydroxystannate (MSn(OH)6, M = Fe, Co, Mn) for epoxy resin, J. Nanopart. Res. 27 (2025) 1-15. https://doi.org/10.1007/s11051-025-06223-3
[27] W.H. Pan, W.J. Yang, C.X. Wei, L.Y. Hao, H.D. Lu, W. Yang, Recent advances in zinc hydroxystannate-based flame retardant polymer blends, Polym. 14 (2022) 1-15. https://doi.org/10.3390/polym14112175
[28] N. Gobile, D.C. Onwudiwe, O.A. Oyewo, Zinc stannate modified graphitic carbon nitride for the photocatalytic reduction of Cr (VI) to Cr (III), Northwest University (South Africa), Dissertation (2022).
[29] S. Lin, Y. Cao, Z. Liu, Y. Li, J. Qian, K. Zheng, J. Jiang, X. Chu, Experimental and mechanistic study on the flame propagation behaviors of corn starch deflagration inhibited by different powder inhibitors, Fire Mater. 49 (2025) 1205-1216. https://doi.org/10.1002/fam.70013
[30] Y.X. Guo, J.H. Liu, W.P. Gates, C.H. Zhou, 2020. Organo-modification of montmorillonite, Clays Clay Miner. 68 (2020) 601-622. https://doi.org/10.1007/s42860-020-00098-2
[31] A.B. Mapossa, N. Mohammad Mehdipour, U. Sundararaj, Thermal, mechanical, flammability properties, and morphologies of polypropylene/calcium carbonate‐based on carbon nanomaterials and layered silicates composites: A future perspective of new sheet material for flooring application, J. Vinyl Addit. Technol. 31 (2025) 146-181. https://doi.org/10.1002/vnl.22162
[32] Y. Lei, X. Zhao, L. Xu, H. Li, J. Liang, G.H. Yeoh, W. Wang, Natural flame retardant minerals for advanced epoxy composites, Fire 7 (2024) 1-20. https://doi.org/10.3390/fire7090308
[33] R. Yadav, A.K. Sharma, S. Sharma, Advanced development in natural graphite material and its applications: a review, Min. Metall. Explor. 42 (2025) 361-385. https://doi.org/10.1007/s42461-024-01167-z
[34] G. Beyer, Chapter 1 – Introduction to flame retardant systems, in Flame retardant nanocomposites, in: T. Sabu, V. Henri, S. Lakshmipriya (Eds.), Flame retardant nanocomposites, Woodhead Publishing, 2024, pp.1-22. https://doi.org/10.1016/B978-0-443-15421-8.00011-2
[35] T.L. Mhlabeni, E.B. Chemere, T. Jamiru, W. Mhike, Flame retardancy of biopolymers enhanced by bio-based flame retardants: a review, J. Fire Sci. 43 (2025) 79-114. https://doi.org/10.1177/07349041241309308
[36] E. Głowińska, P. Wiśniewska, E. Movahedifar, M.E. Penoff, O. Das, H. Vahabi, M.R. Saeb, Cone calorimetry ranking of unsaturated polyester thermoset resins using flame retardancy index (FRI), J. Therm. Anal. Calorim. 150 (2025) 7489-7506. https://doi.org/10.1007/s10973-025-14149-0
[37] R. Sauerwein, Chapter 3 – Mineral filler flame retardants, in: A.B. Morgan, Non‐halogenated flame retardant handbook (2nd Ed.), Scrivener Publishing LLC, 2022, pp.101-168. https://doi.org/10.1002/9781119752240.ch3
[38] S. Sajan, D.P. Selvaraj, A review on polymer matrix composite materials and their applications, Mater. Today Proc. 47 (2021) 5493-5498. https://doi.org/10.1016/j.matpr.2021.08.034
[39] A. Kumar, S. Dixit, S. Singh, S. Sreenivasa, P.S. Bains, R. Sharma, Recent developments in the mechanical properties and recycling of fiber‐reinforced polymer composites, Polym. Compos. 46 (2025) 3883-3908. https://doi.org/10.1002/pc.29261
[40] Y.H. Kim, S. Kumar, X. Li, S.Y. Kim, D.H. Shin, Temperature-dependent mechanical properties and material modifications of carbon fiber composites for optimized structures in high-end industrial applications, Compos. B Eng. 303 (2025) 1-25. https://doi.org/10.1016/j.compositesb.2025.112602
[41] W. Jilani, A. Bouzidi, M. Al-Dossari, I.S. Yahia, Impact of tributyl phosphate on epoxy polymer-based composites: Investigation of their composites’ structural, optical, and dielectric properties for optoelectronic applications, Inorg. Chem. Commun. 174 (2025) 1-15. https://doi.org/10.1016/j.inoche.2025.114036
[42] J.J. Fekiač, M. Krbata, M. Kohutiar, R. Janík, L. Kakošová, A. Breznická, M. Eckert, P. Mikuš, Comprehensive review: optimization of epoxy composites, mechanical properties, & technological trends, Polym. 17 (2025) 1-39. https://doi.org/10.3390/polym17030271
[43] A. Salehi, M. Kheradmandkeysomi, R. Rahmati, S.S. Rahman, M. Fashandi, C.B. Park, Tailoring interfacial, rheological, and energy absorption properties of in situ nanofibrillated ethylene propylene diene monomer rubber for enhanced toughness in polypropylene composites, ACS Appl. Polym. Mater. 7 (2025) 2250-2264. https://doi.org/10.1021/acsapm.4c03204
[44] S. Hong, J. Yang, S. Ahn, Y. Mun, G. Lee, Flame retardant performance of various UL94 classified materials exposed to external ignition sources, Fire Mater. 28 (2004) 25-31. https://doi.org/10.1002/fam.840
[45] T.R. Hull, Chapter 11 – Challenges in fire testing: reaction to fire tests and assessment of fire toxicity, in: A.R. Horrocks, D. Price (Eds.), Advances in fire retardant materials, Woodhead Publishing, 2008, pp.255-290. https://doi.org/10.1533/9781845694701.2.255
