How are commercial aircraft insulated and what kind of fire barrier material is being used? How much insulation is required in a typical Boeing 747 vs. a Boeing 787?
This article from Boeing describes fire safety on their planes, and they mention "fire-protective insulation blankets." A quick google search suggests that in non-aviation contexts, these are usually ceramic fiber. So it seems likely that at least one form of fire insulation in modern transport-class aircraft is ceramic fiber fire blankets.