The amount of impregnated wood removed from the service is increasing daily, and the trend is going to continue in the future. This type of wood cannot be simply disposed or burnt, and storing it at waste depository is only a short-term solution. The material will either have to be disposed of in some way or its toxic components will have to be reduced. The research nowadays focuses mainly on recycling and reusing of impregnated wood removed from its service. We tried to define what properties/qualities of particleboards made from impregnated wood, removed from its service, would be. Particles made from electric posts treated by CCA impregnation 50 years ago were used. Several of these particles were washed with tap water. Their properties were then compared to those of unwashed particles, clean fir particles, industrial particles and bio-remedied particles. Later 1-layered particleboards were prepared from all above mentioned types of particles. The following tests were performed: adherence of particleboards, sieve analysis, chemical analysis with infrared spectroscopy, and calculation of mass loss to samples after exposure to wood decay fungi. The experiments showed, that the mechanical properties of such boards decreases, while biological remained unchanged. Unleached particles could be used for middle layer, for instance. However, this portion should not exceed 10 % - 20 % of the total amount. As this particles still contains some biocides, they are suitable for outdoors purposes mainly.