Fire protection materials are divided into three grades: noncombustible materials, quasi-noncombustible materials, and flame retardant materials. These are certified by the Minister of Land, Infrastructure, Transport and Tourism.

(1) Noncombustible materials (Building Standards Act Article 2 Clause 9, Enforcement Ordinance Article 108 Clause 2)

Materials that if heated by fire in the event of ordinary fire does not burn for 20 minutes after the start of heating, does not cause deformation, melting, cracking or other damage harmful for fire prevention and does not generate smoke or gas harmful for evacuation.
This applies to materials as follows: concrete, brick, tile, ceramic tile, asbestos slate, fiber reinforced cement board, glass fiber mixed cement board (thickness of 3 mm or more), fiber mixed calcium silicate board (thickness 5 mm or more), steel, aluminum, glass, mortar, plaster, stone, gypsum board (thickness 12 mm or more), rock wool, glass wool board. (Ministry of Land, Infrastructure, Transport and Tourism Public Notice No. 1400 Year 2000)

(2) Quasi-noncombustible materials (Building Standards Act Enforcement Ordinance Article 1 Clause 5)

Materials that if heated by fire in the event of ordinary fire does not burn for 10 minutes after the start of heating, does not cause deformation, melting, cracking or other damage harmful for fire prevention and does not generate smoke or gas harmful for evacuation.
This applies to materials as follows: noncombustible material, gypsum board (thickness of 9 mm or more), wood cement board (thickness of 15 mm or more), hard wood chip cement board (thickness of 9 mm or more, bulk density of 0.9 or more), wood chip cement board (thickness of 30 mm or more, bulk density of 0.5 or more), pulp cement board (thickness of 6 mm or more), etc. (Ministry of Land, Infrastructure, Transport and Tourism Public Notice No. 1401 Year 2000)

(3) Flame retardant materials (Building Standards Act Enforcement Ordinance Article 1 Clause 6)

Materials that if heated by fire in the event of ordinary fire does not burn for 5 minutes after the start of heating, does not cause deformation, melting, cracking or other damage harmful for fire prevention and does not generate smoke or gas harmful for evacuation.
This applies to materials as follows: quasi-noncombustible material, flame retardant board (thickness of 5.5 mm or more), gypsum board (thickness of 7 mm or more), etc. (Ministry of Land, Infrastructure, Transport and Tourism Public Notice No. 1402 Year 2000)
However, in the case of using for exterior finishing of buildings, it is not required to not generate harmful smoke or gas during evacuation.