First rainfall since Tianjin explosion leaves city covered in mysterious white foam

The first rainfall to wash over Tianjin since a series of blasts struck a warehouse in the Binhai district last week has sparked a new wave of concern as an unidentified white foam has appeared on the streets.
Some who made contact with it are reporting a burning sensation on their face and lips, while others are reporting a stinging sensation on their arms. Some have said they experienced an itchy sensation, according to a NetEase News report.

Meteorological experts said Monday that rainfall would no longer pose direct danger to people's health, according to a CCTV News report.

However, authorities had expressed concern that the downpour, aside from hampering rescue efforts, would spread harmful substances across the city, after around 700 tons of sodium cyanide—a toxic chemical that creates a combustable substance when it meets with water—was found at the blast site.
Officials today said that at least 40 types of dangerous chemicals were detected at the blast zone, including 800 tons of ammonium nitrate and 500 tons of potassium nitrate, the Guardian reports.

Bao Jingling, chief engineer for the Tianjin Environmental Protection Bureau, previously said in an NBC News report that "if there is rain, it will produce hydrogen cyanide, so we are monitoring it closely," adding that the military's anti-chemical warfare division had been sent to the site on Sunday and the situation "currently...isn't very serious".
Hydrogen cyanide gas is described by the US Centers for Disease Control and Prevention as being a “rapidly fatal” toxic chemical that can reduce the body's ability to use oxygen.

In preparation for the rain, authorities reportedly built cofferdams around a 100,000-square-meter core area of the explosions which will be continually reinforced to prevent contaminated water from flowing out, Xinhua said.
Local monitoring centers reported a normal air quality reading in the city, and the Tianjin deputy mayor in charge of work safety said at a press conference yesterday that sodium cyanide within a three-kilometer radius of the core blast site would be neutralized by yesterday evening.

A total of 114 people have been confirmed dead with 70 more missing after two huge explosions and one smaller blast ripped through a warehouse storing hazardous materials last Wednesday.