Which property of mineral wool makes it effective in fire protection?

Mineral wool's effectiveness in fire protection is primarily due to its non-combustibility. This means that it does not ignite and cannot contribute to the spread of fire, making it a crucial material for firestopping applications. When subjected to high temperatures, mineral wool can withstand direct flames without burning, helping to maintain the integrity of fire-rated assemblies and preventing the passage of heat, smoke, and flames through openings in walls, floors, and ceilings.

While other properties, such as low thermal conductivity, high compressive strength, and flexibility, do contribute to the overall performance of mineral wool in various applications, it is the non-combustibility that directly addresses the key requirement for fire protection. This unique characteristic is what enables mineral wool to be widely used in fire-resistant construction, enhancing the safety of structures by reducing fire risks.