1, light hazard level: hotels and office buildings with a building height of 24m or less. Only the buildings in the closed system are set in the walkways.

2. Medium risk level: high-rise civil buildings: hotels, office buildings, comprehensive buildings, postal buildings, financial and telecommunications buildings, command and dispatch buildings, radio and television buildings (towers), etc.

(1), public buildings (including single-storey and multi-storey buildings): hospitals, sanatoriums, libraries (except stacks), archives, exhibition halls (halls), theaters, concert halls and auditoriums (except stages) and other entertainment places, railway stations, airports, docks and shopping malls with a total construction area of less than 5,000m2.

(2) Cultural heritage buildings: ancient wooden buildings and national cultural relics protection units.

(3) Industrial buildings: food, household appliances, glass products and other factories, such as building components such as preparation workshop, cold storage and steel roof truss.

(4) Civil buildings: stacks, stages (except grape stands), car parking lots, shopping malls, underground shopping malls with a total construction area of 5000m2 or above, etc.

(5) Industrial buildings: material preparation and production workshops of cotton, wool, hemp, chemical fiber textiles, fabrics and products, wood, wood and plywood, grain processing, tobacco and products, drinking wine (except beer), leather and products, paper and paper products, pharmaceuticals and other factories.

3. Serious danger level: the material preparation workshops of printing plants, alcoholic products, flammable liquid products and other factories.

(1), flammable liquid spraying operation area, solid flammable materials, flammable aerosol products, solvents, paints, asphalt products and other factories, as well as production workshops, studios and the lower part of the stage "grape trellis".

4. Warehouse risk level: food, tobacco and alcohol, incombustible articles packed in wooden cases and cartons, shelf areas of warehouse-type shopping malls, etc.

(1), wood, paper, leather, grain and its products, cotton, wool, hemp, chemical fiber and its products, household appliances, cables, Class B plastics and rubber and its products, steel-plastic mixed materials products, various incombustible articles packed in plastic bottles and warehouses where various articles are mixed.

(2), a group of plastics and rubber and its products, asphalt products, etc.

Extended data

A, the classification of fire resistance limit

The fire resistance limit of building components refers to the fire resistance test conducted according to the time-temperature standard curve of building components, which is expressed by the number of hours from the time it is subjected to fire to the time when it loses its supporting capacity or integrity or loses its fire protection function. The specific judgment conditions are as follows:

1, lost support ability

2. Integrity is destroyed

3. Loss of fire protection function

Second, the classification of combustion performance

The combustion performance of components can be divided into three categories:

1, incombustible: building components made of incombustible materials, such as natural stone.

2. Combustible: that is, building components made of flammable or combustible materials, such as wood.

3. Refractory: that is, building components made of refractory materials or building components made of combustible materials with incombustible materials as protective layers, such as asphalt concrete components.

Fourth, the purpose of determining the fire resistance rating of buildings is mainly to make buildings with different uses have corresponding fire resistance, so as to realize the unity of safety and economy.

In order to determine the fire resistance rating of buildings, the following factors are mainly considered:

1. The importance of architecture.

2. Fire hazard of buildings.

3. The height of the building.

4. Fire load of buildings.

References:

Baidu encyclopedia-fire risk rating

References:

Baidu encyclopedia-building fire resistance rating