At around 4.50 p.m., an outbreak of fire occurred on a pallet box of about 650l containing used nickel-cadmium batteries, in a lorry for the transport of dangerous goods, during its transport. The pallet and its content started to melt. On arriving at the parking lot, the driver detected the overheating and used an extinguisher to bring it under control. The material damage was confined to the pallet box and the inside wall of the lorry.

The overheating occurred after loading the pallet box on the hazardous waste collection site. At receiving inspection on this site, the visual verification of the quality of its content proved correct. It was loaded with other pallet boxes of used batteries to be removed to a treatment centre. 

The event was due to a short circuit. The packing of the used nickel-cadmium batteries on 2 levels in a 650l pallet box separated by an insulant, a small plasticised honeycombed sheet (in accordance with the recommendations mentioned in the ADR Agreement), did not prove sufficiently strong to prevent the short circuit. The battery terminals were apparently not individually protected against short circuits.

First, the insulating layer between the 2 levels of used batteries was reinforced. The technicians were made aware of the need to check the presence of this insulating material. Then, the operator of the collection centre defined new rules for the transport conditions of used nickel-cadmium batteries in order to prevent any risk of a short circuit:

• a single loading level;
• the batteries must be removed from their metal base;
• the connectors must be removed.