1, first-class fire protection grade: buildings with a fire resistance limit of not less than 3 hours, such as high-rise buildings and hospitals.
2. Secondary fire protection rating: theaters, libraries and other buildings with a fire resistance limit of not less than 2 hours.
3. Class III fire protection rating: buildings with fire resistance limit not less than 1 hour, such as schools and office buildings.
4. Four-level fire protection rating: buildings with a fire resistance limit of not less than 0.5 hours, such as shopping malls and supermarkets.
5. Five-level fire protection rating: buildings with a fire resistance limit of not less than 0.25 hours, such as warehouses and garages.