Fire destroyed 500 m² of a warehouse used to store nitrocellulose from a paint and varnish plant. Three fire-fighters were incapacitated from inhaling smoke during the response. The 4 t stock of nitrocellulose was lost, and side window panes allowing light to enter the building burst due to the heat. Flames burned the wooden structural frame, and the tile roof collapsed into the building. The police was ordered to conduct an investigation, while the forensics team performed on-site sampling.
One of the hypotheses favoured, due to the high (heat wave) temperatures preceding the blaze and the 5-day absence of personnel (annual plant closure), was evaporation of the wetting agent (isopropanol, ethanol or butanol) leading to a solvent concentration of less than 25%. Under such conditions, the nitrocellulose was capable of spontaneously igniting. The design of this insulated building composed of 4 cells separated by walls, which themselves were surrounded by an enclosure, helped prevent the fire from spreading to the facility’s other installations.
Nonetheless, inspection authorities noted a number of non-compliant aspects with respect to the Prefectural authorisation order: a storage cell not equipped with a smoke removal system, wood frame with a tile roof, premises not fitted with an upper exhaust, building doors with sideways openings, and pallets stacked against the storage room wall. An emergency order imposed that the operator:
- adopt interim environmental protection measures;
- submit a report on the causes of this fire and its consequences for plant installations, machinery and the environment;
- commission a revised safety report, in the aim of rebuilding the nitrocellulose storage cell (which would determine conditions for the facility to resume operations).
Several other measures were also taken: maintaining the damaged installation in a permanent safe operating mode, in accordance with the methodology the operator was to submit to Inspection Authorities; disposing of all wastes in installations specifically authorised for this purpose; and monitoring the water table. In light of results from a hydrogeological study, the operator was ordered to execute the full set of required actions.
