In a factory making zirconium, titanium and hafnium products, two sub contracted technicians exited a workshop where zirconium rods were being cold-pressed to take a break. As one of them lit a cigarette, his clothes instantaneously ignited. He sustained 3rd-degree burns over 50% of his body and 1st-degree burns over another 45% and died 4 days later. The second technician was burned on the forearm while trying to rescue his colleague.
Soil samples and analyses at the spot of the accident were undertaken by the factory operator: the heavy presence of zirconium fines within the samples assessed seemed to confirm the hypothesis whereby the source of ignition was the soil and not the technician’s clothing (since his workstation remained relatively clean, and operator’s tests on the fire-prone nature of clothing were inconclusive).
The search for accident causes pointed to soil pollution by effluent laden with hydrofluoric acid, nitric acid and zirconium fines originating from a metallurgical control laboratory located nearby, whose discharges were collected in the sewer network. Via administrative order, the Inspection Authorities for Classified Facilities requested all operations suspended at the particular laboratory while awaiting: the outcome of additional investigations aimed at evaluating the risks generated by zirconium fines accumulating in soils, installation of a retention system for the fines produced, and repairs to the laboratory’s aqueous effluent discharge network. The operator was also required to: conduct within 24 hours an inventory of all sources throughout the facility capable of producing zirconium fines and sludge; complete within 10 days a study on the identified soil pollution; and perform within 3 weeks a full inspection of the condition of site collection networks dedicated to industrial residual water.
