Noncombustible divisions are a material made from silicic acid calcium which neither burns or gives off flammable vapors in sufficient quantity for ignition when heated up to 750oC.
All exposed surfaces of a ships bulkheads, linings, and ceilings are required to be covered with this material.
The material listed below has a density of 0.65 gm/cm3, which satisfies the requirements for class B divisions according to the 1983 SOLAS regulations.