1. Fireproof grade an is a flame retardant material without ignition point and thermal insulation effect. At present, it mainly involves glass beads, closed hole expanded perlite, rock wool, mineral wool, glass wool, phenolic board, cement-based or gypsum based inorganic thermal insulation mortar and light self thermal insulation system.

2.耐火級B1是根據材料的耐火等級限度確定的耐火隔熱材料。此外，不同部位的材料劃分也不同!燃燒性能：指材料和(或)產品在燃燒時發生的所有物理和/或化學變化，即對火的反應特性。

2. Fire resistance grade B1 is a fire-resistant and thermal insulation material determined according to the fire resistance rating limit of the material. In addition, the material division of different parts is also different! Combustion performance: refers to all physical and / or chemical changes of materials and / or products during combustion, i.e. reaction characteristics to fire.

3.B2級是一種可燃保溫材料，又稱阻燃材料，主要是隔熱材料，添加適量的阻燃劑。它們大多是EPS膨脹聚苯乙烯板和XPS擠塑聚苯乙烯板，我們通常稱之為通用板。這種材料的燃點低，燃燒過程中釋放大量有害氣體。

3. Class B2 is a combustible thermal insulation material, also known as flame retardant material. It is mainly thermal insulation material, and an appropriate amount of flame retardant is added. Most of them are EPS expanded polystyrene board and XPS extruded polystyrene board, which we usually call general board. This material has a low ignition point and releases a large amount of harmful gases during combustion.

4.防火級B3武漢泡沫板是一種易燃保溫材料，常用作聚苯乙烯泡沫塑料的主要材料，由于該材料易燒，目前已從外墻保溫材料中淘汰。

4. fire grade B3 Wuhan foam board is a kind of flammable and thermal insulation material. It is commonly used as the main material of styrofoam, because it is easy to burn, it has been eliminated from external wall insulation materials.