(VOVworld) - The chemicals stored at the Tianjin warehouse where two explosions occurred last week have been identified.

Rescuers are sterilized after cleanup work at the core blast area in Tianjin, north China, Aug. 19, 2015.(Photo: Xinhua)

At a press conference on Wednesday, the vice mayor of Tianjin, He Shushan, said the warehouse stored about 40 substances in seven categories, including approximately 1,300 tons of oxide compounds, mainly potassium nitrate and ammonium nitrate; 500 tons of inflammable materials, consisting mainly of metallic sodium and magnesium; and 700 tons of highly toxic substances, mainly sodium cyanide. He added that caffeine had also been stored at the site. Most of the chemicals were detected at the center of the blast site, around which cofferdams have been installed to reduce contamination. Vice mayor Shushan said about 100 kilograms of chemicals had been found within a three-kilometer radius of the blast center.