What type of firestopping material releases chemically bound molecules of water when exposed to heat?

The type of firestopping material that releases chemically bound molecules of water when exposed to heat is endothermic material. These materials work by absorbing heat during a fire, which leads to the release of water vapor. This process cools the immediate environment and can help prevent the spread of fire and smoke. The presence of water vapor also helps to dilute flammable gases.

In contrast, exothermic materials release energy in the form of heat when they respond to a fire, which can contribute to fire spread rather than impede it. Thermal is a more general term that does not specifically define a firestopping mechanism related to fire resistance. Non-combustible materials refer broadly to substances that do not ignite or burn, but they do not necessarily have the specific cooling and fire-retardant properties associated with endothermic materials.