What is the fire rating standard for rock wool boards used in construction?

Label film

The fireproof grade standard of rock wool board for construction is mainly based on GB 8624-2012 “Classification of Combustion Performance of Building Materials and Products” and other relevant standards, as follows:
Grade A (non-combustible materials)
Grade A1: It is non-combustible and does not produce open flames. It is the highest fireproof grade, with excellent fire safety, almost no combustion, and can effectively prevent the spread of fire in a fire, and will not release heat and toxic smoke. It can be used in building environments with extremely high requirements for fire resistance, such as high-rise buildings, important public facilities, machine rooms and other key parts.
Grade A2: It is also a non-combustible material, but smoke needs to be measured and smoke performance is required to be qualified. In addition to the non-combustible characteristics, it has certain index requirements for smoke generation and other aspects, and is more suitable for some places with strict restrictions on smoke concentration.
Grade B1 (flame-retardant material): It has good flame retardant effect, is difficult to catch fire when exposed to open flames or high temperatures in the air, is not easy to spread quickly, and the combustion stops immediately when the fire source is removed. It is generally used in building parts that have certain requirements for fire protection but are slightly lower than Class A requirements, such as exterior wall insulation, roof insulation, and ordinary partition walls of general buildings.