Abstract
Results of investigation on fungitoxic value of the three formulations of wood preservatives based on the quaternary ammonium compounds (lauryldimethylbenzylammonium chloride, lauryldimethylbenzylammonium bromide, alkylbenzyldimethylammonium chloride) in relation to the surface wood colouring (moulds) and soft-rot fungi have been presented. The agar-plate (screening) and agar-wood plate for moulding fungi and vermiculite-block methods for soft-rot fungi were applied. A high effectiveness of the formulations was proved.