A slow-burning fire ignited at 2:35 pm inside a 1,000-m² painting workshop at a rubber products plant.

The plant operator had been removing paint residue deposits from the floor of the spray-on coating booth biannually. For this purpose, plant operations had ceased as of the previous day, and a subcontractor was stripping the floor when fire broke out near the cardboard placed in front of the applicator, which had been shut off, locked out and had its fluid lines closed. The cardboard burned in emitting no flame but instead thick smoke. The subcontractor alerted the on-call fire-fighting unit, which in turn sounded the fire siren. All 140 employees were evacuated. The plant’s fire-fighters used extinguishers and deployed a fire hose cabinet yet were unable to control the blaze. They then requested backup from the municipal fire department and proceeded to open the workshop outlets, close retention basin valves in order to confine the extinguishing water and cut off the zone’s incoming utility lines. Fire-fighters extinguished the fire around 4 pm using foam and carbon dioxide, while ventilating the workshop. Personnel returned to work at 4:15 and the emergency response was wrapped up at 4:30. The chemical risk squad performed an ambient air analysis that showed no toxicity. The extinguishing water was pumped, assessed and ultimately discharged as waste. The applicator remained intact. Inspectors of Classified Facilities were informed of the fire at 5:20.

This outbreak was due to a series of causes:

• the chipping hammer used for cleaning got hot;
• the cardboard placed to protect the floor in front of the applicator had become caked and partially impregnated with a xylene solvent loaded into the applicator.

The full scope of cleaning had not been carried out in October due to time constraints; the maintenance method (“TPM” standard: Total Productive Maintenance) had not been implemented; the adhesive had flowed onto the floor owing to poor machine design; use of the spray gun was excessive and its refurbishment shoddy; and lastly the conveyor belt reinforcement had fallen due a defective support and incomplete fastening.

Subsequent to this incident, maintenance and cleaning were resumed in adopting additional protection measures, namely: the permanent presence of an in-house fire-fighter, wetting of the zone before and after carrying out work, deployment of a mobile foam unit next to the applicator, and procurement of a hot work permit. The operator modified the applicator’s operating ranges and correctly enforced the TPM standard.

The following corrective measures were implemented:

• revising the applicator instructions with inclusion of an annual schedule for coordinating works acceptance;
• increasing the cardboard replacement frequency and introducing aluminium protection beneath the cardboard to prevent it from sticking to the floor;
• adding a retention basin and modifying the filter support;
• training conducted by the spray gun manufacturer focusing on best maintenance practices;
• setting up an impermeability test (stuffing box, etc.);
• inserting a systematic cleaning phase at the end of each campaign change (removal of parts present in the booth).