Table 1Classes of reaction to fire performance for wood-based panelsProduct | EN product standard | End use condition | Minimum density(kg/m3) | Minimum thickness(mm) | Class(excluding floorings) | Class(floorings)Cement-bonded particleboard | EN 634-2 | without an air gap behind the panel | 1000 | 10 | B-s1, d0 | Bfl-s1Fibreboard, hard | EN 622-2 | without an air gap behind the wood-based panel | 900 | 6 | D-s2, d0 | Dfl-s1Fibreboard, hard | EN 622-2 | with a closed air gap not more than 22 mm behind the wood-based panel | 900 | 6 | D-s2, d2 | —Particleboard,, | EN 312 | without an air gap behind the wood-based panel | 600 | 9 | D-s2, d0 | Dfl-s1Fibreboard, hard and medium,, | EN 622-2EN 622-3MDF,, | EN 622-5MDF,, | EN 300Plywood,, | EN 636 | -“- | 400 | 9 | D-s2, d0 | Dfl-s1Solid wood panel,, | EN 13353 | 12Flaxboard,, | EN 15197 | -“- | 450 | 15 | D-s2, d0 | Dfl-s1Particleboard, | EN 312 | with a closed or an open air gap not more than 22 mm behind the wood-based panel | 600 | 9 | D-s2, d2 | —Fibreboard, hard and medium, | EN 622-2EN 622-3MDF, | EN 622-5OSB, | EN 300Plywood, | EN 636 | -“- | 400 | 9 | D-s2, d2 | —Solid wood panel, | EN 13353 | 12Particleboard, | EN 312 | with a closed air gap behind the wood-based panel | 600 | 15 | D-s2, d0 | Dfl-s1Fibreboard, medium, | EN 622-3MDF, | EN 622-5OSB, | EN 300Plywood, | EN 636 | -“- | 400 | 15 | D-s2, d1 | Dfl-s1Solid wood panel, | EN 13353 | D-s2, d0Flaxboard, | EN 15197 | -“- | 450 | 15 | D-s2, d0 | Dfl-s1Particleboard, | EN 312 | with an open air gap behind the wood-based panel | 600 | 18 | D-s2, d0 | Dfl-s1Fibreboard, medium, | EN 622-3MDF, | EN 622-5OSB, | EN 300Plywood, | EN 636 | -“- | 400 | 18 | D-s2, d0 | Dfl-s1Solid wood panel, | EN 13353Flaxboard, | EN 15197 | -“- | 450 | 18 | D-s2, d0 | Dfl-s1Particleboard | EN 312 | any | 600 | 3 | E | EflOSB | EN 300MDF | EN 622-5 | -“- | 400 | 3 | E | Efl250 | 9 | E | EflPlywood | EN 636 | -“- | 400 | 3 | E | EflFibreboard, hard | EN 622-2 | -“- | 900 | 3 | E | EflFibreboard, medium | EN 622-3 | -“- | 400 | 9 | E | EflFibreboard, soft | EN 622-4 | -“- | 250 | 9 | E | Efl