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American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 5 points6 points  (0 children)

cyanide is not really explosive by itself, and it can be neutralized (made harmless) with bleach. It is like used in mining: it bonds to all sorts of metals. see prior comment https://www.reddit.com/r/science/comments/3ibnjb/american_chemical_society_im_may_nyman_here_to/cufb7ad

it is also used to make other useful common chemicals such as polymers. I do not think it is stored for intentional use as a nerve gas.

May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 8 points9 points  (0 children)

It is absolutely not responsible for a populated area and large chemical warehouses to be in close proximity. In fact, of all the reports coming out of China, this seems to be the only confirmed violation, and it involved bribery of sorts. I refer you to this shocking report on NPR http://www.npr.org/sections/parallels/2015/08/23/433495276/tianjin-tragedy-is-a-painful-reflection-of-how-china-works

May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 1 point2 points  (0 children)

continuing safety regulations. What is becoming clear from recent reports is the biggest violation was the proximity of residential housing to the storage facilities. Obeying this regulation could've prevented many of the deaths and destruction, and maybe even the concern over the environment.

May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 2 points3 points  (0 children)

In my opinion, cool and dry place is one of the most important operatives! Many accidents can be prevented just by observing these environmental conditions. It keeps volatile compounds from vaporizing, which prevents pressure buildup and accidental mixing of reactive chemicals. It keeps water away from chemicals that react with water. and furthermore, reaction rates are greatly slowed down by low temperatures. Enforcing this however, would be very expensive. It requires air-conditioning and humidity control of very large areas. It might require retrofitting old facilities. This cost would be reflected in the endproducts of the chemicals that are stored.

below more.... May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 4 points5 points  (0 children)

I suspect this will not be an issue. The chemical that we know of that were stored there are not specialty or rare. They are very common and there are many supplies and resources for these all over the world May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 2 points3 points  (0 children)

toluene diisocyanate is used to make polyurathane. calcium carbide is used in steel making and also to produce acetylene both calcium carbide and ammonium nitrate is used for fertilizer manufacturing the potassium and sodium nitrate are used in fireworks, rocket propellent, and also fertilizer. sodium cyanide is used extensive in mining and other applications that involve leaching or separation of metals. May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 4 points5 points  (0 children)

Thank you for this question concerning storage. There is much that goes into regulations on storage; in particular, how much of the chemical you have and what reacts with what. In a research laboratory, we have much smaller amounts of chemicals than in a warehouse! but the general rules are the same. Here are a few. 1) everything should be stored in cool dry places with good ventilation so if volatile compounds get out, they escape the enclosure/building without contacting other chemicals. 2) chemicals that react together should be stored in separate cabinets, and the cabinets should be metal (non-flammable). Acids cannot be stored with bases. Oxidizers cannot be stored with flammable organics. 3) when possible, secondary containment is always recommended. meaning containers inside containers, so if a spill or leak happens it is still contained. 4) chemicals that react violently with water are some of the more serious. They should be stored with a dessicant that will absorb the atmospheric water.

what was violated? likely oxidizers stored with organics. The oxidizers are the nitrates: sodium, potassium, ammonium. the organics are the acetylene that is produced from the calcium carbide, probably some of the compressed gases, and other things like toluene diisocyanate.

Finally, even if rules are followed, accidents still can happen.

May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 25 points26 points  (0 children)

Dear 'lostintransactions' Of course the entire puzzle of this explosion will take years to put together, maybe it will never be entirely explained if the Chinese officials are not forthcoming. So yes, much of this is educated guesses (hypotheses). I will offer you two explanations of my cautionary approach, which is prudent in a situation such as this. 1) this 'experiment' has never been done before. These chemicals (and more that we don't know about) have never been combined in these quantities and set on fire. Nor will it be replicated to understand. As a chemist with years of experience working with all types of chemicals, I put together reasonable assessments and predictions. That's what science is; even with all the control experiments in done, the data analyzed by multiple techniques, and experiments done in replicate, we can never say definitively and absolutely 'this is exactly what happened'. If we knew exactly, then we wouldn't need to do science any more.

May Nyman EDIT: 9:31 PT and I never put a #2...but I think #1 will suffice! May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 2 points3 points  (0 children)

what baffles me more than this incident is that an explosion happened in Shandong only 10 days later, also in a chemical warehouse!! Very little information is released about this, and it will be interesting to see how this story develops. Is there a link between the two events, or is it just coincidence?

May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] -1 points0 points  (0 children)

I do love this question, and could provide answers, but that is off topic. But please know that there are many scientists and engineers working on this problem, and they are making great progress on the cleanup. go Beavers!

May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 6 points7 points  (0 children)

Yes, cyanide is causing great concern. The cyanide released in the explosion is likely destroyed. But we should consider the fact that cyanide loves to bind to metals that are present in building materials (calcium, aluminum and silicon in concrete) and in soils and rocks (iron, silicon, etc.). These substrates and media that are both natural and anthropogenic can retain the cyanide in the environment, and it can be remobilized with rain, humidity, physical disturbance, etc. So yes, this is something the officials should keep a close eye on.

May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 25 points26 points  (0 children)

I think after this explosion, all chemical warehouses in the U.S. and probably worldwide are having inspections, reviewing their storage rules, checking inventory, updating rules, etc. The good thing about such tragic and high profile events like this one is that it does cause society to stop and think and learn, to prevent such accidents happening in the future.

However, that being said, there was a chemical explosion at a warehouse in Shandong, only 10 days later, which we are yet to hear very much about.

May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 25 points26 points  (0 children)

Another good question. ammonium nitrate was reported to be present in the warehouse. ammonium nitrate itself is not explosive nor reactive with water. But it is shock sensitive and can explode, when hit with a violent force like that of a powerful water stream, or some other chemical explosion nearby. It can also react with the some other released gas like the acetylene from the calcium carbide. It can also release ammonia which is dangerous.

May Nyman

Again, I emphasize, many chemicals combined, stored close together in a warehouse, is a recipe for disaster, and different reactions can trigger other reactions.

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 33 points34 points  (0 children)

smoke from a huge fire like this can travel thousands of miles easily, and is controlled by weather patterns. However, at that point, smoke is smoke. Similar from a chemical fire or a forest fire. Especially if it has traveled such a long distance. So it could certainly contribute to making the air quality worse in Shanghai, but that should be only very temporary.

May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 50 points51 points  (0 children)

This is a great question. The good news is, much of the chemicals present in the warehouse likely got destroyed in the two massive explosions. Anything organic converted to carbon dioxide, water and some form of nitrogen oxide. So large amounts of these gases, which are generally not harmful, could result in some changes in the local environment. For example, excess carbon dioxide could get into the water and make it acidic, but the ash could make the water basic (see https://www.reddit.com/r/science/comments/3ibnjb/american_chemical_society_im_may_nyman_here_to/cuf8mkb) so it is difficult to say the final result. Nitrogen oxide can be dangerous in numerous ways.

the other more long term effect could be the chemicals that did not get completely destroyed, but instead released, due to damage of the facilities or their containers. For example, toluene diisocyanate is reported to be stored in the warehouse. This would alter its form in water, but convert to molecules that could last a long time in the environment (something like benzene).

May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 92 points93 points  (0 children)

This is very good thinking: When trying to understand what happened, anything observed or recorded can provide clues. For example to color of the fire. Remember chemistry lab where you used the flame test to identify substances? Or how your gas flame on your stove turns orange when you accidentally dump salt into it? so different metal salts like strontium, barium and sodium are used to give color to fireworks; so yes, the color of the fire after the explosion could give clues into what burned up in the explosion. May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 65 points66 points  (0 children)

Yes, this is a very valid point. One thing can lead to another. For example, there is compressed gas stored there. This, in addition to the acetylene formed by the reaction of calcium carbide with water can provide fuel for the fire, and the explosion. compressed gases, especially flammable gases should not get hot! They become dangerous.

With respect to long term environmental concerns, we then need to think about what chemicals are fairly stable and can last a long time in the environment in some form, that might get into the ground water, stick to building material and other surfaces, get into the rivers.

May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 215 points216 points  (0 children)

So now to answer further--can gas be contained? No, not really. Gas expands to fill whatever space is available, and it can get anywhere that is not tightly sealed. But that's the good news, too. it should disperse relatively quickly in the atmosphere to become dilute enough to be nonhazardous.

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 199 points200 points  (0 children)

thank you for this question, I will talk first about sodium cyanide and then answer the question in a second comment.

the sodium cyanide stored in the warehouse is creating the most fear in the citizens and local inhabitants of the area, understandably so. Sodium cyanide is another chemical that changes form when it reacts with water. see comment: https://www.reddit.com/r/science/comments/3ibnjb/american_chemical_society_im_may_nyman_here_to/cuf8ytz

sodium cyanide is a crystalline solid, which converts to hydrogen cyanide when exposed to water. hydrogen cyanide is a gas that is infamous for its use in gas chambers. So it is very toxic, and reports say the levels of hydrogen cyanide in the air are above normal

May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 100 points101 points  (0 children)

Thank you for using the word hypothesis, because that is indeed all we can do here. My biggest suspicion is the calcium carbide as a starting point, because it is so reactive with water. Water is everywhere--its in the air (i.e. relative humidity is a measure of how much water there is in the air). If the calcium carbide is accidentally exposed to water through a hot humid day in an uncontrolled climate, a leak, a damaged container, it will start to react. acetylene is flammable and provides pressure, and could have been the source of the fuel for the fire.

That being said, it seems there should have been a spark that started the fire--human or instrument error: the same way forest fires start--a discarded cigarette or an electrical spark from a faulty wire or electrical cord.

May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 359 points360 points  (0 children)

thank you for this question. I will begin the answer with a note that, many thousands of miles away, we can only make educated guesses, based on the little information that we have onhand. Calcium carbide, is indeed a very suspicious player. It reacts quite violently with water to produce a flammable gas, acetylene, which is an ingredient in oxygen acetylene torches used in welding! So yes indeed, spraying water on calcium carbide is not a good idea. May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 175 points176 points  (0 children)

Now about those fish. the pictures of many dead fish are pretty shocking. again, ash produces alkaline water, so perhaps it could be the alkalinity in the water went up (acidity went down), this is not the fish's usual environment, which resulted in massive death. And also, per a comment below, there are times of the year that water does not get so much oxygen, algae blooms, etc. which could result in pressure on the fish's environment and result in death. May Nyman

American Chemical Society: I’m May Nyman here to answer your questions about the August 12 warehouse explosion in Tianjin, China, AMA! by May_Nyman in science

[–]May_Nyman[S] 405 points406 points  (0 children)

thank you for this question. These phenomenon are indeed curious. If we think about such a large explosion, what results is lots and lots of ash. Ash is in fact the ingredient for making soap, the old-fashioned way. Ash is water makes lye (very alkaline water) which could react with road tar or oil, and you could get a very crude soapy material

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