At around 4:00 p.m., a fire broke out at a 300 m² building used to store solid ammonium nitrate fertiliser (3 t divided amongst five FIBCs / Big Bags weighing 600 kg each) at a farmers’ co-op. The contents in two of the FIBCs remained solid, but the contents in the three others melted and mixed with combustible materials. A 200-m cordon was set up (distance according to the models made for an equivalent TNT of 10%). It took the firefighters eight hours to extinguish the flames.

Consequences

The storage building, its contents (which included 3.7 t of ammonium nitrate 33.5%) and the adjoining buildings were all destroyed. Damage was calculated at €80,000. Three people were temporarily laid off. A portion of the fertiliser (1.18 t) vaporised and/or was diluted by the firewater or rain. Because the unburnt fertiliser had mixed with other products, its stability was not guaranteed. The authorities managed the incident as part of an emergency prefectural order. Resources to prevent and protect against risks related to fertiliser and fire-caused waste were defined by an expert. In the end, 2.66 t of fertiliser was neutralised with magnesium carbonate and disposed of via an approved route.

Building not designed for storage

A garden bonfire that had been lit by a neighbour spread to the co-op’s storage building. It was no longer supposed to be used by the co-op. With the town hall’s permission, it was now being used by the recreation committee to store its equipment. As a result, it was not suitable for storing fertiliser. Exactly why FIBCs of fertiliser were inside it is unknown. According to the operator, ammonium nitrate should not have been inside the building (see the co-op’s operating and safety instructions).

Measures taken

All the staff at the co-op (warehouse workers) were reminded about the storage instructions. The operator also plans to monitor existing procedures and improve the training of technicians.