An explosion that was not followed by a fire occurred at around 9.30 am on a heavy fuel oil tank in the heating facility of a ready-made meal production plant. The tank, installed 8 months earlier, contained 145 t of hydrocarbons. An external company was carrying out welding work on the vents at the time of the accident. Seven employees standing nearby suffered from shock and hearing problems. A safety perimeter was set up around the storage area. The tank did not collapse, only its roof was projected onto the roof of the operations building where the sterilisers were located, damaging it. An external company pumped the heavy fuel oil contained in the retention area. As a preventive measure, the operator retained the site by blocking the rainwater network. Probably due to the combined action of the explosion (movement of pipes) and thermal shock (fuel oil at 70 °C, wall at 0 °C), cracks appeared at around 1.20 pm in the basin’s wall allowing fuel oil to seep through, which rapidly solidified. The pumping operations were interrupted and the safety perimeter was extended. Following technical advice, pumping was resumed but the fuel oil normally maintained at 70 °C, solidified on contact with the air and the company encountered difficulties. In total, 6 dump trucks were needed to recover all of the fuel oil. The operation ended at around 10 pm.