At 15h30, in a chemical plant, an outdoor tank collapsed, causing the spill of 30 m3 of hydrochloric acid solution on the ground. A gas cloud formed, which was abated in 20 min with a water curtain (according to the results of the hydrochloric acid measurements carried out with a Drager detector). The off-site emergency plan was activated, the production process was shut down and the recovered acid was neutralized and disposed by an authorised company. The costs of the tank rupture was estimated at 70,000 euros and those of the waste disposal at 8,500 euros.

The tank was made of glass fibre reinforced polyester ; it stood on four metallic legs also coated with polyester fibres. Hydrochloric acid penetration through the pores of the tank might have caused corrosion of the metal-legs of the tank, which could not bee observed due to the external coating.

The operator gave up the use of polyester tanks for this kind of substances and, the coating of metal parts with polyester fibre which does not allow operators to visually check for corrosion.