Which characteristic is important for effective firestop products?

High temperature resistance is a key characteristic for effective firestop products because it ensures that the material can withstand the extreme heat generated during a fire without failing. Firestop systems are designed to prevent the spread of flames, smoke, and hot gases through openings in walls, floors, and ceilings. To be effective, the firestop products must not only seal these openings but also maintain their integrity and performance in high-temperature conditions. This property helps to protect life and property by containing fire and smoke, thereby allowing for more time for evacuation and potentially minimizing damage to the structure.

Other characteristics, though they may contribute to the overall usability of a product, do not directly influence its effectiveness in fire prevention and containment as significantly as high temperature resistance does.