Last Wednesday, a chemical storage facility in Tianjin, a city in northeastern China, exploded. Several blasts occurred over about a minute, and the resulting fires burned throughout the weekend, leading to eight further explosions on Saturday. Over a hundred people were killed, and hundreds more are injured or missing. 

This, you’d think, would be bad enough – but as it turns out, chemical explosions have repercussions which reverberate beyond the initial massive explosions and raging fires.

On Monday night, it rained in Tianjin for the first time since the explosion. The rain which left behind a mysterious white foam and reports of stinging skin and lips from those who came into contact with it. These pictures show the foam the rain left behind, on a public square and on what appears to be a car window: 

Image: NetEase.

It’s unclear what exactly the foam contains, but authorities have announced that the rainfall is safe. The local Bureau of Environmental Protection measured levels of cyanide in the foam and found it normal, while several officials stood in the rain for ten minutes and reported no stinging or itching. Bao Jingling, chief engineer at the bureau, told China Daily that local hospitals had reported no cases of poisoning thus far. 


Authorities became particularly concerned about the effects of rainfall after around 700 tons of sodium cyanide, which reacts wth water to produce a poisonous and combustable gas, was found at the blast site. On Sunday, before the rain started, the military anti-chemical warfare division was dispatched to the site, authorities have built a 100m by 100m network of “cofferdams”, which enclose areas of water and soil and should prevent runoff of contaminated water from the site. 

Since the initial explosions, ten executives of the company which owned the warehouse have been detained, following questions over the company’s license to store hazardous chemicals.