Abstract: Apparatus and method for preventing and extinguishing fires in storage silos containing flammable materials, especially biomass. A liquid carbon dioxide storage vessel has a liquid outlet supplying at least two flow paths. At least one of the flow paths supplies gaseous carbon dioxide to a storage silo for controlling smouldering fires, and the at least one other flow path supplies carbon dioxide vapour and carbon dioxide snow to the storage silo for fire extinguishing. The liquid carbon dioxide vessel may be arranged to supply gaseous and liquid carbon dioxide to more than one storage silo.