A fire broke out at around 11 a.m. in a stockpile of 1.5 t of manufacturing residues (ammonium sulphate, grape pulp, crushed cocoa pods, compost, starch) located in a 100 m² storage facility at the base of the hoppers leading to the basement of the product building’s silos in a plant producing organic soil amendments. Smoke on piping exiting a crusher, the fan of which was in operation, and the smell of smoke alerted an operator at around 11:30 a.m. The windsocks above the crusher were burning. Three employees took them down and attempted to put out the flames with fire extinguishers. The fumes released by the slow [self] combustion of the organic materials made them ill. They evacuated the facility before being taken to the hospital by the emergency services. The fire brigade evacuated the employees and set up a 100 m safety perimeter. The site’s electrical power was switched off. The cramped facility was no longer ventilated after the electrical power had been shut off and was only accessible via a hatch. The temperature had risen to 400 °C. Spraying down the facility’s access hatch with water had no effect. At around 6 p.m., firefighters equipped with self-contained breathing apparatus, due to the high CO and NH3 content, decided to evacuate the stock of material at the surface using buckets hoisted by ropes, and then soak it down with water. One of the firefighters was the victim of heat stroke. The waste from the fire was disposed of by an approved waste disposal company.

Sparks, generated by an employee welding on the auger under the hopper located above the room’s hatch, were responsible for triggering the self-combustion of the stockpile of residues. The analysis of the accident showed the following:

• failure to clean the risk areas and transfer components (base of the hopper, elevators, conveyor belts, belts, etc.) due to a peak in activity and the absence of adequate cleaning equipment (cleaning hammer) resulted in the accumulation of organic matter on the ground and in the room where the fire occurred;
• no fire permit for the welding operations performed in hazardous areas;
• exacerbation of the accident due to the containment and a lack of ventilation in the room.

The operator set up hot work procedures in hazardous areas and regular cleaning of the installations.