A method for fireproofing or flameproofing boards made with organic material/materials, fibers or particles selected from the group of wood fibers, wood particles, wood strands, plant particles and material selected from seeds, husks, straw, shells of nuts or seeds or mixtures thereof or glued boards comprising one or more layers of textiles or textile fibers, or resin boards comprising a resin matrix with dispersed fibers and/or particles of wood fibers, wood chips, wood strands, one or more layers of textiles, textile fibers, plant particles selected from seeds, husks, shells of nuts or seeds and/or mixtures thereof, wherein a fireproofing or flameproofing composition is induced to the organic material during production of the boards, in which organic material is passed from a storage and to a board forming station via a resin mixing or blending chamber, which can be a resin blending section at the end of a rotary drier, and wherein a binder or a matrix forming resin is added to the organic material by mixing the binder or resin into the organic material by injecting the binder or resin and subsequently forming the blend into boards to obtain the final composite board containing the organic material, and wherein the method further comprises adding a flame-retardant composition to the organic material, by
- a. injecting a liquid aqueous flame-retardant and latent hardener composition comprising a blend of diammonium hydrogen phosphate (DAP) and monoammonium dihydrogen phosphate (MAP), wherein the blend of DAP and MAP in weight ratios ranges from 95% DAP/5% MAP to 60% DAP/40% MAP, and from 0.1 up to 15% by weight of total solids of one or more acids selected from the group consisting of organic acid, C2-C7 organic acid, citric acid, formic acid, acetic acid, malic acid, tartaric acid, oxalic acid, lactic acid, butyric acid, strong acid, hydrochloric acid, and any mixtures thereof, the liquid composition being an aqueous composition comprising a liquid aqueous solution of the contents ranging from 25% w/w to 80% w/w of the blend, into the organic material and where the liquid aqueous flame-retardant and latent hardener composition is added prior to and/or in parallel to the binder or the matrix forming resin,
- b. adding a solid blend of the flame-retardant and latent hardener composition comprising a blend of DAP and MAP, wherein the blend of DAP and MAP in weight ratios ranges from 95% DAP/5% MAP to 60% DAP/40% MAP, and from 0.1 up to 15% by weight of total solids of one or more acids selected from the group consisting of organic acid, C2-C7 organic acid, citric acid, formic acid, acetic acid, malic acid, tartaric acid, oxalic acid, lactic acid, butyric acid, strong acid, hydrochloric acid, and any mixtures thereof, to the organic material in an intermediate mixing step provided between the storage or a refiner and the board forming steps in a board production line, or
- c. injecting the liquid aqueous flame-retardant and latent hardener composition onto one or more layers of textiles during transfer from the storage and to the board forming station, and where the liquid aqueous flame-retardant and latent hardener composition is added prior to and/or in parallel to the binder or the matrix forming resin.