As much as 3,000 tonnes of hazardous chemicals were stored in a logistics centre in the Chinese port city of Tianjin, a police spokesman said on Monday. The announcement came after massive explosions ripped apart the centre last week, killing at least 114 people and injuring more than 700 others.

Six days after the blasts last Wednesday, authorities are still struggling to determine the nature and amount of chemicals stored on the site because cargo records were destroyed in the blasts and subsequent fires.

Raging fire followed explosions in Tianjin on August 12. Photo: Baidu

Niu Yueguang, deputy director of the Public Security Bureau’s Fire Department, told CCTV that about 3,000 tonnes of hazardous chemicals were confirmed to have been stored in a Ruihai International Logistics warehouse, where the explosions originated.

“Over 40 kinds of hazardous chemicals [were stored on site]. As far as we know, there were ammonium nitrate and potassium nitrate,” Niu said. “According to what we know so far, all together there should have been around 3,000 tonnes.”

Earlier media reports said 700 tonnes of the highly toxic sodium cyanide were stored in the warehouse.

Solid sodium cyanide is fatal if ingested or absorbed through open wounds, an expert from the Beijing University of Chemical Technology told CCTV. Authorities have been spraying alkaline peroxide on the explosion site to neutralise the chemical, the state broadcaster said.

It is not yet known how much of the stored chemicals have ignited. The impact of one of the explosions last Wednesday night was the equivalent of a magnitude 2.9 earthquake, according to the China Earthquake Network Centre.

Vivienne Zeng

Vivienne Zeng is a journalist from China with three years' experience covering Hong Kong and mainland affairs. She has an MA in journalism from the University of Hong Kong. Her work has been featured on outlets such as Al Jazeera+ and MSNBC.