Pollution
Humain
Environnement
Economique

In a hazardous waste treatment centre, a fire broke out on a stock of fifteen 1-tonne big-bags containing shot blasting waste, consisting mainly of aluminium. Local residents sounded the alarm at around 11:30 p.m. The fire brigade, accompanied by an employee, noticed 2 m-high flames in the storage area. At around 0:15 a.m., employees at the site were able to extinguish the metal fire by smothering it with inert materials (a layer of earth, and then a second layer of clay). The clay layer was removed 2 weeks later. The waste was then transferred to the deactivation pit for 2 weeks and then stored in a hazardous waste cell. The soil and clays used to smother the fire were also stored in a hazardous waste cell. The costs of the disposal operations were evaluated at €10,000.

The big-bags had been delivered to the site that same day. On the day of the fire, it began to rain at around 9:45 p.m., lasting for an hour. The aluminium contained in the waste stored in big-bags reacted with the water to form dihydrogen, which ignites upon contact with air. This oxidation reaction of aluminium is highly exothermic.

The receiving controls in place at the time of delivery did not allow this particularly water-reactive waste to be detected. Such waste was not intended to be stored at the site. Following reactivity tests performed on the samples provided by the waste producer, it was asked not to deliver specific waste material having a powerful reaction with water. It is thought that misidentification of the big-bags at the producer resulted in their delivery to the treatment centre.

The instructions for waste pending treatment did not indicate that big-bags had to be protected from the elements. On the other hand, the site’s surveillance camera did not allow the storage area in question to be viewed.

The operator has since adjusted its security cameras. The procedure has also been modified to ensure that water-reactive waste is stored in locations protected from the elements (e.g. covered with Polyane sheeting).