Sunday, March 27, 2016

What is the smell of TATP?

First, my condolences to anyone who is living in the Brussels area. These bombings are terrible. From a New York Times article (by Andrew Higgins and Kimiko de Freytas-Tamura) about the terrorists' preparation of the explosive triacetone triperoxide, an interesting detail: 
...Mr. Rodrigues said that Ibrahim and Khalid el-Bakraoui were his first tenants, and that they had provided him with fake identity papers and bogus pay slips to obtain a one-year lease. Three others, including a man since identified as Mr. Laachraoui, visited regularly. 
The smell in their apartment was horrendous, the owner said, recalling how he had seen on the floor two large fans similar to ones found on construction sites, and an exhaust fan on the wall. Such fans would be useful in the final stages of preparing TATP, the homemade peroxide-based explosives used in the bombings on Tuesday, and also by the November suicide bombers in Paris. 
After breaking into the apartment on Tuesday morning, police officers found 30 pounds of TATP — enough for another powerful bomb — as well as nearly 40 gallons of acetone and eight gallons of hydrogen peroxide, materials used in producing TATP. They also found a suitcase full of nails and metal bolts, used to make bombs more lethal, as well as an Islamic State flag. 
Mr. Rodrigues said that whenever he visited the apartment, the door to the living room was always shut, while windows throughout the apartment were always open. Mr. Rodrigues said he would smell a “very strong chemical odor” that he could not quite put a finger on. “If it smelled like bleach or drugs, I would’ve recognized it,” he said....
OK, I know what acetone smells like, and I know what 50% hydrogen peroxide smells like. Do they really smell so bad? I like the smell of acetone, and 50% hydrogen peroxide just smells sour-ish to me. Here's NYT correspondent C.J. Chivers on Twitter:
TATP production often involves multiple distinct odors, at different stages. Sounds like odors were noted, no one acted. 
So I am not asking anyone to give me a detailed treatise on the making of TATP (although I seem to recall one (ok, just a simple synthetic procedure) in JACS a few years back), but what's the smell of making TATP? 

19 comments:

  1. I can tell you that pure acetonperoxide has a strong and rather pleasant minty-camphoric smell, like car air freshener tree

    However if you use hydrochloric acid to catalyze the reaction and fail to cool it enough, you get a very lacrymatory chloroacetone in the reaction mix

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  2. I should add that the smell of acetonperoxide is not a clean "minty-camphor terpenic", there is "something else" note in it. I think if you smelled TEMPO radical, acetonperoxide comes quite close. But this is all from a distant memory, more than 30 years ago

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    1. Ahh, okay, TEMPO has a nice minty sharp smell, there's something not quite right about it as well, but nothing I can put my finger on as "unpleasant" per se.

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  3. 30 pounds of acetone peroxide?? Dear lord. I'm amazed it didn't detonate under its own weight, much less in packing the devices. I'm pretty sure that AkzoNobel is recruiting process chemists with cajones of that grade (minus the malice, of course).

    Jokes aside, I'd bet the strongest smells were from acetone, perhaps with hints of the HCl used to catalyze the reaction. These are both pretty volatile. Consider the scale, too: tens of gallons of acetone in a cheap flat.

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    1. well these guys aspire to be suicide bombers, so I suppose they are not too worried about the workplace safety standards. Also, my understanding is that they don't cook up 30 pounds of acetonperoxide in a bathtub at once - I would imagine making a number of smalle batches, that are easier to manage and they would probably store the material in a moist form in a fridge up to a moment when they were ready to use it, One of the biggest risks with acetonperoxide is sublimation that forms larger crystals around the container lid, and gradual decomposition due to leftover acid use in catalysis. 30 pounds is an insane quantity to be sure, but these are not exactly sane people.

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    2. I discussed TATP in lecture the day after the bombings.

      Supposedly there is a tin(IV) catalyzed paper out there for the synthesis, but I can't help but wonder if it is a "false flag" operation. Either way I do not intend to find out.

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    3. The stuff isn't hard to make, even normal bright elementary school kid can figure it out, or download it from web. Fortunately many of these jihadi dudes do not possess good technical knowledge so they do the same shitty thing over and over again - I was actually surprised about that printer cartridge plot few years back (plane bombing with printer cartridges loaded with PETN), which was not brilliant but at least it was less amateurish than the rest. You know these guys don't have to be too bright, just lucky, once. But given how long they have been trying... Even the working class Irishmen could do better than acetonperoxide crap.

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    4. If I remember correctly, "Fenian Fire" (The Fenians being the primordial IRA) was phosphorous (likely red) dissolved in carbon disulphide. Drop a bottle of that down the chimney and let it do its work.

      The scary part is that I would hazard many of the potential people have an engineering background, as that is a job of respect (but not necessarily employment) in the region of the world where many of the plotters originate.

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  4. It's little consolation to their victims, but the fact that terrorists are resorting to such desperate means must be a success in its own right. Regulating the supply of nitrates has lowered the quality of their weapons. On the other hand, their expertise in handling TATP is unsettling. To make so much of the stuff without an accident implies they've found best practices. The sheer quantity here challenges my long-standing assumptions about TATP. I always thought of it as stuff kids play with until someone loses a finger.

    On the other hand, commercial organic peroxides such as Trigonox 301 (a cyclic 2-butanone peroxide trimer) are stored and used in solution without much remark. Some time ago I was studying their contribution to VOC's in rheology-controlled polypropylene. Before AkzoNobel ships such things on a pilot scale, they insist on seeing your site and assessing its capability to safely handle their peroxides. They must have had incidents in the past.

    Good point about the sublimation of TATP. With enough around, that would contribute to odors. That still raises the question of how long these lunatics were storing it for their landlord to remark on its smell. Those larger crystals around the container lid (or even refrigerator door) have been a cause of unintended decomposition, too.

    What does the bombsquad even do when they encounter 30 lbs of TATP in an apartment (besides canceling every other appointment that day)?

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    1. TATP can probably be stabilized for disposal. You could perhaps wick some high-boiling, non-reducing liquid into the pile (fluorinated oils?) and scoop the goo for disposal by chemical reduction or burning in a trench.

      Definitely an exciting proposition, though.

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  5. On a loosely related subject - it seems to me that rigging tannerite with a detonator would be as easy if not easier than making and attempting to control TATP. Tannerite is widely available in the US. Google it and you'll see what I mean. Am I off base or shouldn't people be more concerned about the ready availability of this explosive?

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    1. Regarding the Belgium incidents, one suspects (though I do not know) that Tannerite is not available in Europe?

      Certainly plenty of Things that Go Boom in the US, though.

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    2. Should work, this was on Yahoo today:
      http://www.guns.com/2016/03/25/georgia-man-loses-leg-in-binary-target-explosion-video/

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    3. dry ammonium nitrate (the oxidizing ingredient of tannerite) is not so easy to obtain in Europe without raising some red flags to the police. After the precedence of the Oklahoma city bombing I'm suprised to hear that stuff like tannerite is still freely available in the US.

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  6. 30 pounds? Why don't these [blankety-blank] people ever weed themselves out of the Darwinian pool before they blow up others? Or perhaps we simply hear about the ones who sadly fail to do so.

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  7. The New York Times article doesn't stack up, especially with the comments above. That aside, kudos to Chemjobber for raising the point, as a chemist I see an amazing lack of critical analysis from other chemists of these terrorist bombing stories. I remember the London bombings ... from a chemistry point of view, it just didn't stack up.

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  8. One of the things that I should note here is that initial news reports are probably based on 2nd- or 3rd-hand reports from people who were on the scene, so I could believe that there are errors regarding the amounts of TATP, etc.

    That said, I believe the reports of there being strong smells, etc.

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  9. A century ago terrorists (then called "revolutionaries") were commonly chilling their own nitroglycerin in sink bowls. Non-purified nitro is much more capricious than the white powder... Even with nitro evolution didn't process the idea out of our genes, though.

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    1. think you mean "anarchists", possibly "bolsheviks"

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