The use of solid biomass is already dominant among RES not only in the South Baltic but in the European Federation as a whole and is expected to grow. With this, not only emissions from combustion but also emissions from storage and handling are apt to increase.The storage and handling of biomass is, however, not free from risks and problems.The current report discusses some of the risks associated with the large-scale handling and storage of biomass with special emphasis on the processes occurring during storage and the mechanisms behind auto-ignition.The report contains experimental results and information on different biomasses and their characteristics, with focus on the characteristics affecting the storage and handling properties. It is intended to be useful when planning for the use of different biomasses, leading to the need of storage.