The chemical cyanide has been detected in high levels in the port city of Tianjin. As of Wednesday, the chemicals were 350 times standard limits and had been detected at the 25 water sites within the enclosed area of the blast site. "An excessive level of cyanide was detected in eight locations with the highest reaching 356 times," said Tianjin Environmental Protection Bureau, according to Agence France-Presse

"Cyanide pollution is severe inside the warning zone. Outside the zone overall, the amount of cyanide detected is at normal range.," said Tian Weiyong, a Ministry of Environmental Protection official, according to CNN.

All polluted water is blocked in the blast area. "It won't be discharged before reaching to the normal quality standard," said Deng Xiaowen, a Tianjin Environmental Monitoring official, CNN reported.

The government confirmed the presence of sodium cyanide in sewer pipes below the Binhai New Area port zone where the blast took place. The pipes have been sealed to contain the chemical. Hydrogen peroxide has been sprayed on the wreckage caused by the explosion to prevent the sodium cyanide from releasing deadly hydrogen cyanide gas.

The probability of the presence of an array of chemicals in the water that has yet to be detected is being considered. "There is simply not enough time to conduct a chemical screen to understand the scale of the pollutants, thus not enough understanding on the potential risks," said Wu Yixiu of Greenpeace, according to the New York Times.