In a waste treatment centre, 10 m³ of acid chloride delivered in a vacuum stainless steel tank was transferred to a 22 m³ tank truck. The operation was carried out to dilute the acid before incineration and no other container was available. Right from the start of transfer, an exothermic reaction occurred in the vacuum tank. The delivery truck was isolated but 3 m³ of liquid was released through the vacuum tank’s vent and bursting disc.

The resulting HCl cloud was dispersed by the wind but a stringent odour was observed in the neighbourhood. The emergency services that were informed 30 min after the start of the accident monitored the situation for five hours. Four employees were poisoned.