A reinforced (fibre + resin) polypropylene tank containing 40 tonnes of 27% hydrochloric acid (HCl) ripped open within a chemical plant. The contents spilled into an anti-acid treated retention basin that also included 2 other tanks, one with HCl the other with ferric chloride (FeCl3). This latter tank was also fitted with a secondary retention basin made of concrete without having first undergone an anti-acid treatment. Due to the wave effect, acid made contact with the ferric chloride tank, which also began leaking, with the concrete basin becoming exposed quite quickly to acid attack.

Site firefighters reacted by diluting the acid layer that overflowed into the stormwater network. The pH measurements taken on stormwater collected would not reveal any significant impact.

A manhole fracture on the acid tank would have caused the accident.

The consequences of such an accident could have been much more severe given that the damaged tank could have been containing the 33% HCl fuming at 20°C and meteorological conditions (wind and temperature) proved to be rather favourable.