Wood construction is on the rise. Public timber construction in particular (schools, kindergartens, nursing homes, etc.) is currently the subject of special attention by policy makers. In public construction, for example in care facilities, the fire class of the building must be B-s1, d0. Wood materials can then be used, but they must be surface treated with a fire protection paint or varnish to achieve this fire rating. https://finlex.fi/fi/laki/ajantasa/2017/20170848 Currently commercially available flame retardants use ingredients suspected of being harmful, such as bromine, chlorine or phosphorus. These are suspected to pose a risk of, for example, lymph node cancer and fetal harm. Thus, there is a need for a bio-based and safe raw material for fire protection coating. Cellulose and lignin are known to have promising flame retardant properties. Among other things, VTT has achieved good results with nanocellular-based flame retardants combined with mineral pigment. Instead of nanocell, this project focuses on the potential of microcrystalline cellulose as well as lignin, and also lignin-containing microcrystalline cellulose. At present, a preliminary study is underway at Aalto University, in which the operation of microcrystalline cellulose as a raw material for a fire protection coating is examined by preliminary experiments. The objects of the cellulose-based flame retardant coating are 1) the effect of cellulose crystallinity on the decomposition temperature of the coating 2) the effect of cellulose optical properties (light scattering) on heat radiation absorption in a fire situation 3) formation of a gas barrier 4) the effect of lignin on the Intumescent property of the fire retardant coating, which forms a heat-expanding insulating layer on the substrate to be protected. The aim of these factors is to create cellulose and / or lignin-based fire protection coating and impregnation concepts.