Self-heating occurred in a closed metal storage cell containing 550 tonnes of sunflower cakes in pellet form (an agglomerated and dry by-product) located in a vertical silo of a vegetable oil manufacturing plant. A nitrogen inerting procedure was carried out. As the heating appeared to be under control, the cell was scheduled to be emptied 4 days later. During the operation, however, combustion was discovered in the cakes. The emptying process was interrupted, and nitrogen was injected into the cell from the bottom. Carbon dioxide was also injected into the upper volume of the cell. The Inspection authorities for classified facilities, who were informed the next day (26 July), requested that the facility operator notify the fire and emergency services and take the necessary precautionary measures outlined in the good practices guide for storage silos. Following an inspection conducted on 27 July, the Inspection authorities also requested the creation of an intervention protocol before any further operations on the cell, the creation of a safety perimeter for the responders and increased vigilance for monitoring the removed cakes which could catch on fire again. Attempts were made to remove the product over the next 8 days but this proved to be unsuccessful due either to clogging of the product or renewed combustion; 250 tonnes of cakes remained to be extracted from the cell. The cell was finally cleared out on 6 October.