In an animal feed plant, the temperature started to rise in a silo containing 300 m³ (300 t) of sunflower meal.

It was detected around 6:30 a.m. by the staff during their weekly monitoring round (temperature control, odours, appearance, etc.). The temperature measured was between 15 and 30 °C. The cell was monitored from 6:30 a.m. to 12 p.m., with transfer of its contents to a loading hopper. At 3 p.m., as the temperature at the top of the cell was quite high (27 °C), the operator alerted the emergency services and decided to empty the cell. At 4 p.m., the contents of the cell and the hopper were emptied out onto the exterior slab. The emptying operation ended at 5 a.m. the next day, and the maximum temperature recorded was 64 °C. The inside of the cell, which still contained 5 t of product, was watered down. The emergency team left the premises at around 11:00 a.m. Over the course of the following days, a specialised company was called into to clean out the silo.

The loss of product was estimated at 100K Euros and operating losses at 7,600 Euros. All the sunflower contained in the silo was sent to be methanised to prevent any contamination of the feed produced. Following observations made by the emergency services, the facility operator moved the staff assembly point which was near the slab where the sunflower meal was spread out. The silo’s dry column was renovated (correcting a paint and leakage problem).

After examination, it appeared that the rise in temperature was due to the fermentation of the grain, made possible by the infiltration of rainwater through the silo roof, which had been damaged during a storm in February 2014.