The unlawful use of an ultra-large chlorine container by a rubber plant was responsible for a deadly poisoning incident last week, the work safety watchdog announced on Friday.

The State Administration of Work Safety found that the Lixing rubber plant in Hejian, Hebei province, had installed an oversized container filled with liquefied chlorine in a bid to save on costs.

On the morning of May 13, the tube connecting the container to the chlorine tank truck ruptured, and the resulting chlorine leak led to the deaths of two people and the hospitalization of 25.