Approximately 2 kg of propane were released into the atmosphere at an LPG filling centre (Seveso installation) and designed to supply customers throughout the region.A tank car was moved while it was being loaded, causing a gas leak. Positioned at station P2, the tank car was coupled to a second tank car at the neighbouring station PB and for which the filling operation was nearly complete. When the loading operation was finished, the pump operator removed the tank car’s yokes causing both tank cars to move a distance of 10 m (due to the sloped ground). This thus caused the loading arm to be ripped away from the tank car in position at station P2. The arm on the loading station side was closed by the rupture valve. On the tank car side, the arm was broken along the threads of the rupture valve. Back pressure on the tank car’s bottom valve thus limited the leak. The station’s level detectors did not trip due to the small quantity of gas released and the wind that dispersed the cloud. The incident was attributed to a malfunction of several safety barriers (at both the technical and organisational level). The Classified Installations Inspectorate requested that the operator undertake several corrective actions: a feasibility study regarding the rehabilitation of the loading station site to ensure zero inclination of the track, verification to ensure that 2 chocks (or yokes) are present and identified at each tank car loading station, verification that loading arms were severed at the rupture valve level, awareness training for the operators regarding the formal procedures for installing anti-impact devices…

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