Pollution
Humain
Environnement
Economique

In a lead recycling company operating part time with only partial staff on the job and a melting furnace shut down, the treatment plant manager upon arriving at work at 5 am observed smoke escaping from the used battery storage room. A smouldering fire had ignited during the night on a hundred or so of these batteries, accounting for a total of 1.5 tonnes of lead batteries filled with 20% sulphuric acid, stored in a pit inside the 100-m² building. The belated discovery of this fire occurred subsequent to fire detection system and video surveillance malfunctions.

The manager unsuccessfully attempted to extinguish the fire by spreading the batteries using a material handling apparatus (loader); then, with many staff members arriving to begin their shift, external emergency services were notified at 7:30 am. A safety perimeter was set up and traffic rerouted. The batteries were sprinkled and cooled by fire-fighters using 2 variable flow nozzles. The fire was put out by 11:30 am.

Odours of burnt plastic were noticeable in the vicinity of the plant, and an air pollution incident was feared. Air samples taken on a sampling device located below the main vents and adjacent to the plant were analysed the same day, yielding: Pb = 0.01 µg/m3, Cd < 0.2 ng/m3 (quantification limit), and As = 0.71 ng/m3.

Since the storage hall sat atop the retention basin, the fire extinction water collected was channelled to the physicochemical treatment plant for the site’s process water and then analysed prior to discharge. Operating losses were in fact limited.

The fire had no doubt been smouldering since the previous day at 8:30 pm. No employee had been present in the “crushing” zone and no efficient internal extinction system for a fire of this type had ever been introduced. According to the operator, a short circuit between 2 batteries caused the accident, while the malfunction of the smoke detector damaged the alarm system supply cable. This installation, which was unable to resist the penetration of acidic vapours, had nonetheless been inspected on 29th January, 2009.

Subsequent to this accident, stronger cables were installed to supply the fire detectors, 3 fire hose cabinets and 2 dry standpipes rounded out the intervention system in place before extending the corresponding network grid. Personnel were trained in system use, and a “battery storage fire” procedure was implemented while awaiting issuance of a more general “fire response” procedure. Two self-breathing apparatuses were made available to technicians, who were quickly trained in their appropriate use.

Lastly, a fire and evacuation drill for personnel was scheduled during October 2009 in collaboration with the Departmental fire services unit prior to installing a “plant-wide evacuation” alarm system. The operator also issued a press release.