This post has been updated.
Hundreds of people were injured and dozens were killed after a series of massive explosions took place in the northeast Chinese port city of Tianjin late on Aug. 12. The blast zone is now a wasteland of incinerated cars, crushed shipping containers, and burnt-out buildings.
By Aug. 16, at least 112 had died in the blasts, with 95 missing, including 85 firefighters, state-run Xinhua news agency reported. Around 700 people remained in the hospital, including 57 in serious condition. About 3,500 people have been relocated to 10 nearby schools, the local government said earlier at a press conference. More than 1,000 firefighters, along with military personnel specializing in handling nuclear and biochemical materials, have been sent to the area.
Behind the blasts is Ruihai International Logistics. Any number of dangerous chemicals stored in its warehouse facilities might be the culprit, as Quartz has reported. The government says it cannot confirm which chemicals—or mixture of them—caused the blasts because Ruihai’s facilities were “severely destroyed” (link in Chinese).
A nasty mix of chemicals
One thing is certain: Many toxic materials were released in the blasts.
Chinese officials found 700 tons of sodium cyanide stored at two locations near the blasts, reportedly 70 times the permitted quantity. They said “only small amounts” of the cyanide escaped, and that the air and water outside the evacuation zone is safe. Cyanide can penetrate the skin and cause poisoning.
Earlier tests of sewage water within the blast zone revealed dangerous levels of cyanide, according to a report by national broadcaster CCTV (link in Chinese). Tianjin authorities said sewage water has been blocked in the blast scene and didn’t contaminate surrounding areas.
Nitrates were also stored at the blast site, according to the Beijing News, citing the Tianjin fire department. Among them were potassium nitrate and sodium nitrate. Nitrates are solid oxidizing agents that easily explode when heated or collided.
Tests have also revealed the presence of other chemicals, including caustic soda, hydrogen iodide, sodium hydrosulfide, and sodium sulfide.
Calcium carbide, another chemical known to be contained at the site, can emit flammable gases when it becomes wet. Firefighters at the scene used water initially, but that only made the situation worse when the calcium carbide was exposed, according to the Southern Weekly (link in Chinese). The firefighters then switched to using sand to bury the fire.
Firefighters were never warned against using water, according to one who was among the first deployed at the scene. He was quoted by Southern Weekly while recovering from injuries at the nearby Tianjin Teda Hospital.
“We knew there was calcium carbide inside, but no one knew if the calcium carbide had blasted or ignited at the time,” Lei Jingde, an official with the Tianjin fire department, told state-run digital publication The Paper (link in Chinese). “It doesn’t mean the fire brigade is stupid—knowing calcium carbide but still using water. We definitely didn’t use water wrongly.”
Toluene diisocyanate, which is also highly toxic, is on the list of the chemicals stored at Ruihai’s warehouse. According to samples collected on Thursday morning, toluene levels in the air near the blast site exceeded safe levels by over 54%, Chinese official media reported. After burning in the air, toluene can disturb the endocrine and even the central nervous system of human bodies, as a chemical industry expert explained (link in Chinese) to the media.
Amid concerns of noxious fumes spreading out to neighboring cities like Beijing, the China Meteorological Administration indicated that winds have been coming from the west and southwest, pushing the gases east to the Bohai Sea.
Right next to families
A housing estate is located a mere 600 meters (0.37 miles) away from the blast point, Chinese media reported (link in Chinese). Two other neighborhoods are situated within a thousand meters. Both the developers and the residents of the nearest housing estate said they were not informed Ruihai handles “dangerous chemicals.”
According to regulations (link in Chinese) set by the nation’s work safety administration, facilities over 550 square meters in size that handle and store dangerous chemicals must be at least 1,000 meters (0.62 miles) from surrounding public buildings and facilities. Ruihai’s container yard covers more than 46,000 square meters, according to the company website.
Ruihai didn’t have the license required to handle “dangerous chemicals” when it was established in 2012, reported the Beijing News (link in Chinese). Supposedly, a survey of residents was taken from May 2013 to August 2014 by Tianjin’s environmental authorities, asking for opinions on Ruihai reconstructing its yard for containing dangerous chemicals. In the survey, sent to 130 local residents, 100% of the 128 who responded agreed with the site of the container yard, and 51% supported its reconstruction. But local residents told the Beijing News they had never received such a survey.
Calls made by Quartz to Ruihai were not successful.
China’s chemicals industry is feared
The blasts in the Tianjin port is the latest example of a series of explosions in China’s chemicals industry. In April, an explosion hit the Gulei PX factory in Zhangzhou, leaving 15 injured. It involved paraxylene, used in making polyester fibre and plastics. A similar explosion happened at the same plant in 2013, prompting local officials to promise residents such accidents would never happen again. This year, three other explosions (link in Chinese) occurred in chemical plants across China, as noted by NGOCN, a Guangzhou-based support group for volunteers and NGOs.
In 2013, explosions at a refinery of state-owned PetroChina in the northeastern city of Dalian left two people injured and two missing. The company had five incidents of fires and blasts in just over a year around 2011.
Thousands of people took to the streets in a suburb of Shanghai in June to protest the construction of a chemical plant. They feared the new facility would involve paraxylene. Local officials assured them it would not, but the demonstrations pointed a deep mistrust toward the chemical industry.
Wu Qiang, a political professor at the University of Duisburg-Essen, touched upon this sentiment in a column (link in Chinese) in the Hong Kong-based digital publication The Initium:
A mistrust about the safety and liability of the chemical industry and its management, a suspicion of the political-business relationship, and a fear of the government taking off its responsibility—this is a common mentality of the middle class in China.