An aluminum hydroxide is often adopted as a paper flame retarder.
When I light, water will be aluminum oxide, and occurs in the case. That’s because heat is taken away and it’s the setup I do own fire extinguishing of.
It’s often also adopted as wallpaper of building material.
2Al (OH) 3 ⇒ Al2O3 + 3H2O.
2AlO (OH)⇒ Al2O3 + H2O
There are inorganic phosphorus system, nitrogen containing system compound, aluminum hydroxide and calcium carbonate as other paper flame retarders.
It seems that only the above material is considered as a paper flame retarder so far.
Our boric acid system flame retarder appeared there. Please see following animation.
The very high flame resisting effect can be given.