Early on Sunday 11 December 2005 a gasoline storage tank was being filled from a pipeline at a fuel terminal at Buncefield. Safety systems fitted to prevent the tank overfilling failed and gasoline began to spill from the vents on the tank roof. A low-lying cloud of heavy, flammable vapour accumulated and spread out for about 250m in all directions around the tank. Ignition of the cloud occurred and a powerful vapour cloud explosion devastated the fuel depot. The ensuing fire spread to other tanks and was not fully extinguished for several days. Many nearby businesses were forced to relocate for months or even years causing serious commercial losses.

This paper considers the lessons learned related to emergency preparedness at large flammable sites as a result of this incident. These include the responsibility of the operators of fuel depots, tanker terminals, etc. Examples include: risk assessment, prevention of spillage, detection and shut-off, bunding of tanks, provision of fire water and tertiary containment of fire effluent. However, some of the more fundamental lessons are still being assimilated – for example, the potential for severe explosions in open areas is still not widely used as a basis for safety planning.

Perhaps the most important lesson of all was that our view of the range of hazards faced by large flammable sites was seriously deficient. The high levels of confidence that we had a complete working understanding of flammable risks was not justified. Such attitudes are always dangerous and it is an important responsibility for those with a stake in controlling major flammable risks to be open about this.