In an agrochemical plant, there was an explosion in silo no. 3 in the sulphur handling workshop that housed equipment for mixing, mechanical grinding, storing and packaging 5 tonnes of chemicals. During the explosion, all units of the facility were operational except silo no. 3. The effects of the explosion spread upwards to the top of the lift connecting the 3 silos, as well as to silos 1 and 2. The resulting overpressure was released by the vents of the silos. During the explosion, the maintenance manager was at the foot of the lift whose vent channelled a significant portion of the explosion to the outside. No casualties were reported and the material damage was limited to the facility: 3 to 4 tonnes of ground sulphur stored in the silos and a few parts of the roof were destroyed. Material damage was estimated at 100 K euros and operating losses at 113 K euros. The obsolescence of the upper portion of silo 3 (made of steel in a corroded state while silo 3 and the other silos were in stainless steel) may have caused the explosion. One or several rusted metal plates sticking out from the wall may have ignited the falling microionised sulphur particles. Technical improvements were made in the facilities: maintaining the ground sulphur storage silos in an inert stage outside operating times, use of equipment adapted to product handled, replacement of defective silo and overhaul of facilities.