At about 6:30 a.m. on a Sunday, a fire was detected in a dangerous goods transport (DGT) company classified as a lower-tier SEVESO company. The fire broke out in a parked tanker lorry. With a capacity of 19 t, it contained just 1.5 t of liquefied petroleum gas (LPG). The fire spread to several other tanker lorries. The fire brigade, contacted by a third party, arrived at the scene at 7 a.m. The operator initiated its internal emergency plan, while the emergency services established a security perimeter and sprayed water on the accident.
At 7:15 a.m., the LPG tank erupted in a boiling liquid expanding vapour explosion (BLEVE). At 7:30 a.m., a second tank, containing 2.5t of LPG, also erupted in a BLEVE. Four firefighters, positioned 40 m from the explosion, were slightly injured by the blast. Two other empty tanks exploded shortly thereafter. The emergency services were forced to retreat for 20 minutes, then began spraying water at the fire’s epicentre. Ten fire nozzles, including 4 water cannons were deployed. The fire was brought under control at 8:20 a.m., then finally extinguished at around 10 a.m. Degassing, transfer and inerting operations were performed on four full tanks, three of which were leaking and one containing propane. The firefighting water was contained in the site’s retaining basin.
Extensive material consequences
The zone where the explosions occurred was devastated. The accident generated very intense thermal effects in a diameter of 40 m (and up to 60 m in places) and mechanical effects with pressure effects up to 400 m (and fragments were thrown distances up to 1.5 km). The 2nd tank that experienced a BLEVE was thrown a distance of 150 m. One of the two empty tanks that exploded was thrown 50 m. Fragments from the tanks, some weighing several tonnes, were thrown several hundreds of meters. The company’s administrative buildings, located 200 m away, felt the blast effects: windows were blown out and equipment had fallen to the ground. Twenty or so lorries were destroyed.
The consequences of the accident went beyond the site’s boundaries. A building belonging to a public works construction company, located just a few tens of meters from where the fire started, was skewered by metal elements and it was severely damaged by the blast from the explosions. The company suspended its activity: six people were temporarily laid off (technical unemployment). In all, five neighbouring companies and nine detached homes were damaged.
Consequences of the accident
The prefect issued an emergency order to secure the site. In particular, the order called for an analysis of the causes of the accident. According to the operator’s initial investigations, several fires had started, although no explanation for their origin had been determined at the time. The vehicles involved had been stationary for several days, which ruled out the possibility of the overheating of the rolling parts.
The operator took the following measures following the incident:
- intrusion prevention and detection: the height of the site’s protective fencing was raised to 2.20 m and associated with an intrusion detection system. Video surveillance and lighting were reinforced;
- fire detection: the installation of fire monitoring devices capable of detecting overheating of rolling parts;
- limitation of fire propagation: the operator modified the organisation of the parking area so as to increase the spacing between DGT lorries;
- reduction of hazard potentials: full DGT tanks are prohibited from parking and parking time is limited for partially loaded DGT tanks.
On 01/06/18, the operator was fined €150K, of which €50K was suspended.