F4 Plywood (F Four-Star Plywood)

F4 means F☆☆☆☆ or F 4-star or F Four-star, which is the top Formaldehyde Emission grade for plywood, fiberboard, MDF, OSB, HDF, wood furniture and other wooden products according to Japanese standard JIS A 1460 (2005) Building Boards Determination of formaldehyde emission – Desicator method.

JIS A 1460 (2005) is a part of JAS (Japanese Agricultural Standard) which is published by Ministry of Agriculture, Forestry and Fisheries (MAFF Japan).

JIS A 1460 (2005) sets four grades for Formaldehyde Emission value . F☆☆☆☆ is the highest Formaldehyde Emission grade according to JIS A 1460 (2005). F4 plywood means the plywood can meet the F☆☆☆☆ grades of Formaldehyde Emission according to JIS A 1460 (2005). F4 plywood is the lowest Formaldehyde Emission plywood which can be used interior without limitation.

JAS Formaldehyde Emission grades: Grades (Rating)   Average Value  Max. Value F☆☆☆☆                   0.3mg/L                   0.4mg/L

F☆☆☆                      0.5mg/L                   0.7mg/L

F☆☆                          1.5mg/L                   2.1mg/L

F☆                              5.0mg/L                   7.0mg/L

Note: These values are achieved through Desiccator Test.