MAC: Mines and Communities

Chinese chemical "holocast" at metals port

Published by MAC on 2015-08-16
Source: Al Jazeera, BBC News (2015-08-15)

Toxic sodium cyanide found in deadly mix

The largest chemical explosions in recent history struck the northeastern Chinese city of Tianjin last week. According to the latest report from Reuters (citing state media figures), the death toll has now risen to 112, with 95 people (mostly firefighters) missing, "suggesting the toll will rise significantly".

Tianjin is the world's tenth largest port by container volume, exporting massive quantities of metallic ores, coal, steel, and other materials. It is also one of China's major points of import - specifically of iron ore from companies such as BHP Billiton, Rio Tinto, and Fortescue. According to latest reports, their operations have not been significantly affected.

Local people rose up in anger at being "kept in the dark" by officials about the extent and nature of the disaster, and most of them were evacuated.

Pinpointing the initial cause of the explosions has so far proved difficult - to say the least. They appear to have occurred in a warehouse containing nitrates, then almost instantly spread to other buildings housing various chemicals.

By Saturday (15th August) it was reported that, within this extremely potent toxic mix were no fewer than 700 tonnes of sodium cyanide, whose primary use is in the processing of mined gold , although, just a day later, a government spokesperson was quoted as saying it was "only" a hundred tonnes.

Sodium cyanide is harmful when inhaled or ingested. It's highly poisonous when converted into hydrogen cyanide gas on dissolution or burning - the very conditions that prevailed in Tianjin.

In the third article below, Greenpeace is quoted as saying that itsown tests at the blast site showed local water supplies were not "severely contaminated" by sodium cyanide.

This seems a questionable and complacent conclusion, considering what it is widely known about the poisonous impacts of hydrogen cyanide gas, and the capacity of the chemical to leach toxic heavy metals into the environment.

 
 
 
 

Evacuations as chemical fears grow at China blast site

Fire re-ignites at site of twin blasts in Tianjin, as death toll rises to 85, with more than 700 wounded.

Al Jazeera

15 August 2015

Residents living close to the site of giant explosions in the Chinese port of Tianjin have been evacuated over fears of toxic contamination as new fires ignited.

Armed police were carrying out evacuations within 3km of the blast site on Saturday after highly poisonous sodium cyanide was found, the Beijing News said.

The blaze ignited again at the warehouse where the blasts struck on Wednesday night, with several small blasts heard by reporters from the Xinhua state news agency .

"Out of consideration for toxic substances spreading, the masses nearby have been asked to evacuate," Xinhua reported.

Authorities announced on Saturday that the death toll has risen to 85, with more than 700 others still being treated in hospitals, including 25 who are in critical condition and 33 who are in serious condition.

A survivor was pulled from a shipping container on Saturday morning, state media reported. His identity was not immediately known. Television video showed the man being carried out on a sketcher by a group of soldiers wearing gas masks.

A team of chemical experts has been called in to the site to test for toxic gases.

Shockwaves from the blasts late on Wednesday were felt by residents in apartment blocks kilometres away in the city of 15 million people.

Furious residents and victims' relatives railed against authorities outside a news conference on Saturday for keeping them in the dark as criticism over transparency mounted.

Residents and relatives were prevented from entering the press conference and could be heard shouting outside.

"Nobody has told us anything, we're in the dark, there is no news at all," screamed one middle-aged woman, as she was dragged away by security
personnel.

China has a patchy industrial safety record and the disaster has raised fears of toxic contamination after officials said they were unable to identify precisely what chemicals were at the site at the time.

Tianjin work safety official Gao Huaiyou listed a host of possible substances at the briefing, adding that the firm's recent large exports had included sodium bisulfide, magnesium, sodium, potassium nitrate, ammonium nitrate, and sodium cyanide, among others.

China on Friday defended the work of firefighters who initially hosed water on a blaze in a warehouse storing volatile chemicals, a response foreign experts said could have contributed to the explosions.

The explosions have disrupted the flow of cars, oil, iron ore and other items through the world's 10th largest port.

The blast sent shipping containers tumbling into one another, leaving them in bent, charred piles.

Rows of new cars, lined up on vast lots for distribution across China, were reduced to blackened carcasses.

Tianjin is the 10th largest port in the world by container volume and the seventh largest in China, according to the World Shipping Council, moving more containers than the ports of Rotterdam, Hamburg and Los Angeles.

It handles vast quantities of metal ore, coal, steel, cars and crude oil.

Authorities have only released limited information about the accident, a criticism often levelled at Chinese officials in the aftermath of disasters, and restricted discussion of it online.

More than 360 social media accounts have been shut down or suspended for "spreading rumours" about the blasts, Xinhua reported citing the Cyberspace Administration of China.


China explosions: Potent chemical mix behind Tianjin blasts

BBC News

15 August 2015

Chinese authorities are still trying to ascertain what exactly caused a potent mix of chemicals to ignite in a warehouse in Tianjin late Wednesday, triggering blasts that rocked the city.

The explosions took place at a warehouse owned by Ruihai International Logistics located in Tianjin's port area.

What were the chemicals involved?

Authorities had earlier said that the warehouse contained calcium carbide, potassium nitrate and ammonium nitrate.

Calcium carbide is used in the production of PVC plastic, while the other two chemicals are used in producing fertiliser and dynamite.

There were unconfirmed reports that the warehouse contained 700 tonnes of sodium cyanide, stored in wooden boxes or iron barrels. The chemical is used in the mining industry, among other uses. Police on Saturday confirmed the presence of an unspecified quantity of it near the site.

People's Daily quoted firefighting officials as saying that some of these chemicals would be "easy to explode if heated or collided".

China is the world's largest consumer of hazardous chemicals, says Paul Pang, vice-president of industry analysis firm IHS Chemical in China.

Can they pose a danger to people's health?

In sodium cyanide's case - yes, very. US government health experts say it can be "rapidly fatal" if inhaled or ingested. It is soluble in water - raising concerns in some Chinese media that it may have entered drain water - but its dust is also easy to inhale.

It releases the highly poisonous gas hydrogen cyanide when dissolved or burned.

Potassium nitrate can cause breathing problems and damage to kidneys, while ammonium nitrate can be toxic when burned.

Calcium carbide can be harmful if touched or breathed, and doctors recommend immediately washing affected areas.

One image widely circulated on the Chinese micro-blogging site Weibo, said to be from the disaster site, appeared to show a chemical burning when water was poured on it.

"With such a large fire, inevitably the plume of toxic fumes that have been dispersed could have devastating effects to the public in the future ," says Shane O'Carroll, a chemical safety specialist with Chemstore, a British hazardous materials company.

Mr O'Carroll says sodium cyanide running off into groundwater systems could pose a public health risk, and he said people in Tianjin should consider drinking only bottled water.

How do you store and handle them?

There are standard global safety regulations for producing, transporting and storing hazardous chemicals, but these are extremely numerous and depend on the type of chemical and its toxicity.

China adheres to these rules, but, Mr Pang, of IHS Chemical, says: "The reality is that sometimes these regulations may not be strictly followed, and in some cases, the people working in this industry are not fully trained and qualified for handling hazardous materials."

Chinese law states that businesses dealing in dangerous chemicals must store such materials at least 1km from public buildings and transport networks. But three major residential communities were located within a 1km radius of the Ruihai warehouse, said Global Times.

Other media outlets also reported that a goods loader working for Ruihai claimed he had not been given relevant training.

Some products, such as sodium cyanide, are extremely toxic and highly regulated, and also not easy to contain in event of a spillage.

Mr Pang says: "It is uncommon to have 700 tonnes of sodium cyanide stored in one location."

Mr O'Carroll says all the chemicals should have been stored as far away as possible from each other. "It is evident each should have been segregated as it was inevitable that there would be a disastrous explosion with that combination."

What happens if there's a disaster?

Questions have been raised online over whether firefighters, who reportedly sprayed water on the initial fire before the blasts, followed the right protocol.

Calcium carbide, when mixed with water, produces acetylene gas, which is flammable.

Chemical safety expert David Leggett told Reuters that the acetylene explosion could have detonated the ammonium nitrate.

Mr Pang says that, going by the magnitude of the blasts, the explosions were caused by chemicals such as potassium nitrate igniting.

Industrial safety manuals online state that a calcium carbide fire should be put out using dry powder fire extinguishers, and cleaned up by mixing sand into the chemical.

In the case of a release of sodium cyanide, for example, the United Nations recommends neutralising it with sodium hydroxide.

Potassium nitrate should be picked up using equipment, say experts.


China blasts death toll 112 and likely to rise as scores of firefighters missing

Reuters

16 August 2015

The death toll from massive explosions in China’s port of Tianjin has risen to 112 and 95 people, most of them firefighters, are missing, state media said on Sunday, suggesting the toll will rise significantly.

More than 720 people remain in hospital four days after Wednesday’s disaster, which sent massive yellow and orange fireballs into the sky, rained burning debris on to a vast industrial zone, crumpled cars and shipping containers, burnt out buildings and shattered windows of nearby apartments.

President Xi Jinping on Saturday urged authorities to improve safety and learn lessons paid for with blood.

China evacuated residents who had taken refuge in a school near the site of the blasts on Saturday after a change in wind direction prompted fears that toxic chemical particles could be blown inland.

It was not clear from media reports how many people were evacuated, but the order came as a fire broke out again at the blast site, a warehouse specially designed to store dangerous chemicals, according to Xinhua.

Officials acknowledged the presence of toxins but said they posed no risk to people outside the evacuation zone.

“I can responsibly say that there will be no secondary damage to the people,” Shi Luze, the chief of staff of the People’s Liberation Army’s Beijing Military Region, told reporters, referring to people outside the zone.

Shi confirmed the presence of more than 100 tons of deadly sodium cyanide, stored at two separate sites. He said workers were trying to clear the area of chemicals before possible rain showers, which could create toxic gas.

Greenpeace in an email said its tests around the blast site showed that local water supplies were not severely contaminated with cyanide, but that they did not “disprove the presence of other hazardous chemicals in the water”.

“Greenpeace reiterates its call for authorities to implement a comprehensive survey of hazardous chemicals currently present in air and water supplies and make public all information,” it said.

In an earlier statement, Greenpeace urged the government to establish a five-km (three-mile) evacuation zone.

Some 6,300 people have been displaced by the blasts. Shockwaves were felt by residents in apartment blocks kilometres away in the city of 15 million people.

About 100 people from a residential area near the blast site protested outside a hotel where a government press briefing was held, angry that dangerous chemicals had been stored near their homes.

“I’m very worried that these dangerous chemicals will harm my health,” said Zhang Yinbao, who works in the chemical industry and whose apartment building is only 800 metres from the blast site.

“The government has said they won’t have a big impact, but we have no way to know for sure,” Zhang said, calling for a thorough investigation and compensation.

About three dozen family members of missing fire fighters marched to district government offices where they were dispersed by police after scuffles.

Eighty-five of the 95 missing are fire fighters.

After Wednesday’s blasts, fire crews were criticised for using water to douse flames which may have contributed to the blasts given the volatile nature of the chemicals involved.

Industrial accidents are not uncommon in China following three decades of fast growth. A blast at an auto parts factory killed 75 people a year ago.

Reporting by Megha Rajagopalan and Natalie Thomas in Tianjin. Writing by Michael Martina and Matthew Miller; Editing by Nick Macfie.

 
 
 
 
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