At 00:15 a.m., a fire broke out in a hazardous waste storage facility. Upon seeing flames around a piece of heavy machinery, the operator of a neighbouring company alerted the emergency services, who arrived at the scene 45 minutes later as they had been given the wrong address. The firefighters were unable to enter the site and did not have the operator’s telephone number. They had to contact the security company to open the gate, although the operator was not informed. In the meantime, the fire when out by itself. Once on site, the firefighters could not find any trace of fire due to the darkness and fog.

The next morning, upon arriving at the site, the operator noticed that the hydraulic hose on one of the excavators had melted and that the oil it contained had spilt onto the ground and burned. A self-ignition reaction occurred on a batch of waste from a smelter located near the machinery. This exothermic reaction was linked to the oxidation of the various metals present in the waste. As their waste identification card indicated its flammable and explosive nature, the operator had tested their reactivity (tests of ignition, contact with water and leachate) when they entered the site. These tests did not show any risky behaviour. Other waste, based on the same metals from the same producer, had regularly been stored at the site without any problem. The operator thus accepted the waste and placed it in its storage containers. As it turns out, the waste was unstable under such storage conditions. There was an error in assessing the flammability of the waste under the storage compartment conditions. The machine’s degradation was linked to its proximity to the waste.

After the accident, the operator:

• took organisational measures to facilitate access to the site by firefighters in the case of a fire;
• recontacted the firefighters to finalise the evacuation plan in case of classified fire;
• implemented a foundry waste stabilisation protocol. The latter consists of mixing the metal filings with soil (1/10 metal), then oxidizing them through exposure to rainwater and cement. The stability of the resulting mixture is tested and validated by an industrial safety organisation. This protocol replaces the tests performed at reception;
• has implemented a directive for machine drivers requiring vehicles to be parked more than 15 m from waste.