Perfluoroisobutylene (PFIB)

[MrSamosa]

Perfluoroisobutylene/PFIB/Perfluoroisobutene-- the latter name being the most helpful in doing searches-- is along the lines of the "classic" chemical warfare agents like Phosgene. It stands apart from them, however, by its high toxicity. It is not a lachrymator as much as it is a killer (its LC50 is about 10 times less than that of Phosgene), and it has earned some infamy as the cause of "Polymer fume fever," as a result of overheated Teflon frying pans (more on this in a moment).

It has the structure (CF3)2-C=C-F2 . Basically, 2-isobutene with all of its Hydrogens replaced by Fluorine atoms. In line with the logic behind conventional war gases, it posesses symmetry and is unsatured. It is a volatile gas, which boils at 7*C. It is insoluble in water, and instead decomposes to many nasties like HF, Carbonyl Fluoride (which is, in itself a potent poison), and other Fluorocarbons. This is the same reaction that takes place in contact with the eyes and mucous membranes, naturally.

The synthesis from Teflon (Polytetrafluoroethylene) is as follows, in a series of unbalanced reaction equations to give you a general idea of the process (sorry for the hastiness of this) :

PTFE --> Tetrafluoroethylene

Tetrafluoroethylene --> (CF3)-CF=CF2

(CF3)-CF=CF2 --> (CF3)2-C=CF2

I don't know the specific conditions that drive each reaction, but just that by heating an unfilled Teflon frying pan on a stovetop for a few minutes (less than 10), it will begin to emit toxic fumes-- including Perfluoroisobutene. From a scare-the-sheeple article I found:

In new tests conducted by a university food safety professor, a generic non-stick frying pan preheated on a conventional, electric stovetop burner reached 736°F in three minutes and 20 seconds, with temperatures still rising when the tests were terminated. A Teflon pan reached 721°F in just five minutes under the same test, as measured by a commercially available infrared thermometer. DuPont studies show that the Teflon offgases toxic particulates at 446°F. At 680°F Teflon pans release at least six toxic gases, including two carcinogens, two global pollutants, and MFA, a chemical lethal to humans at low doses. At temperatures that DuPont scientists claim are reached on stovetop drip pans (1000°F), non-stick coatings break down to a chemical warfare agent known as PFIB, and a chemical analog of the WWII nerve gas phosgene.



Gotta love the "nerve gas" Phosgene eh? :D Here (http://tuberose.com/Teflon.html) is the article I got that quote from. A more helpful one, based on sounder science, is
here (http://www.asanltr.com/ASANews-98/pfib.html) . I see much opportunity for PFIB. In comparison to other classic agents, there is relatively little written about this one...and that appeals to old samosa's adventurous side.

EDIT: Well damn. I'm constantly amazed by the amount of information on this forum, and by how much our members know [before me]. Looks like I'm presenting nothing new here.. After feeling a bit insecure, I did a quick search and found everything I've said has been mentioned in the archaic "improvised chemical weapons" thread. Mods- decide what should be done with this; maybe leave it so that PFIB can be addressed specifically instead of lumped together with the hundreds of other "Improvised Chemical Weapons"?

[megalomania]

Might as well leave it here. I might add that scare the sheeple article was actually a television news broadcast. Worse still they showed how the gasses at low ppm can kill household birds.

I wonder how, realisticially, a frying pan can reach 1000 F? Besides the odds of that happening is remote in the extreme because you would have to be quite the dumbass in the first place to turn the stove on an empty pan and forget about it. They make it sound like your home will instantly be filled with a half dozen deadly gasses that will kill all the children. Of course that is what sheeple articles do, stir the flock.

Now then, what would be the practical applications of a teflon based chemical weapon? Even though it is expensive it is a commodity available to just about anyone anywhere. Could such a weapon be deployed in such a way as to appear accidental? Perhaps by oven cooking some teflon tape and wafting the fumes towards a neighbors apartment? Filling a marks home with burned teflon?

I wonder if the emmitted toxic gasses could be trapped in a solvent and later dispersed by some other means? This would at least be an expedient method of easily producing the toxins since very little in the way of chemical knowledge or equiment would be involved if indeed the likes of PFIB can be made by heating Teflon.

A nerve gas indeed... :( What's next, the deadly nerve gas cyanide? The deadly nerve gas ricin? There was already a TV show where the "terrorists" had gaseous ricin (and the TV feds called it a nerve gas).

[MrSamosa]

Powderized Teflon, as used in Pyrotechnics and flares, may provide some opportunities for weaponization, as finer particles can be heated much more quickly. If anything, it would serve as a more practical reagent than a frying pan. Nevertheless, as NBK mentioned in the "Improvised Chemical Weapons" thread, Tetrafluoroethylene is very cheap itself. From the diagram provided by ASA, the only 2 end products shown are Teflon and PFIB. Teflon, I would imagine, would require some other chemical to initiate polymerization, and therefore in its absence, it would be more likely that PFIB would form.

Perhaps, for the purpose of having a usable chemical, the PFIB vapors could be condensed? This may take the form of the common distilling setup, where in the boiling flask is powderized Teflon. No doubt, it would have many impurities, but it would still be more usable than vapory nonsense. However, said impurities may not be a detriment... as the purpose of PFIB is simply to kill, other nasties like Monofluoroacetic Acid (also a potential decomposition product) would not be detrimental :) .

[nbk2000]

If you do a simple destructive distillation of TFE to form the PFIB, then you get all the other nasties as well, which may have a synergistic effect and amplify the toxicity of the mix, compared to neat PFIB.

However, what are the irritating properties of the others, like MFA? If they are much more irritating than the PFIB, they would warn of the CW's presence before the targets get a lethal dose.

I would think a destructive distillation, followed by a fractional distillation of the condensed products, would result in a much more effective product, as the PFIB is supposed to have an irritation threshold above the lethal lethal (for long exposure), so you could gas them with them never feeling a thing. :)

Also, in the ASA article, there's several references to the use of cystine compounds as pre-exposure prophylactics that will protect against lethal exposures of PFIB (and other lung-injurants). THAT is something worth checking into, as I know that l-cystine is used as a conjugant with AKG in an experimental cyanide antidote/prophylactic, having talked to the professor who was researching it for the US Army.

RTPB "Plan for Failure" says you must expect to be exposed to your own CW at some point, and must assume the gasmask to be faulty as well, so you must have layers upon layers of protection when handling CW materials.

Physical distance, physical barriers, chemical barriers, being upwind (outdoors or fumehood), detectors, and medical pre-treatments and antidotes. Oh, and having someone else make, handle, and deploy the stuff for you in a suicide mission neatly solves all of the above risks to yourself. :)

[MrSamosa]

For the poorly equipped amateur with an adventurous side, surely there must be a way to self-treat oneself in case of mild accidents. Although fresh air, ideally pure Oxygen (from a cylindar) is invaluable for this, I am thinking along the lines of OTC cold medicines. It is well known that stimulants are used to clear up problems in the respiratory tract, such as asthma or even a clogged nose. Could ephedrine or pseudoephedrine be used for this purpose, as a possible treatment for such gas exposure? Or, what about DXM, as found in Robitussin as a cough-suppressant? My only thought about Pseudoephedrine is that it increases the heart rate, and this may be dangerous in combination with a toxic gas, which as some members are unlucky enough to know, also greatly increases the heart rate.

Lachrymation is generally easy to deal with... Eye droppers of clean water can clear out the eyes, in the absence of an eye wash. It is important to remember-- DO NOT RUB YOUR EYES. When you feel the initial pang of the gas, it seems like it would comforting to jam your fingers in there... This has quite the opposite effect, especially with gases like CS.

Apparently, inhaling small amounts of Ammonia is effective in treating Chlorine exposure. I don't know about this, since I've heard it only from one source. It seems like a painful treatment though, because Ammonia is just as bad as Chlorine (I'm talking pain, here...this isn't to say anything about toxicities).

[Skean Dhu]

yea , i've heard similar accoutns with regards to primitave 'gas masks' in WWI when CL2 and mustard were new and unexplored soldiers used to use urine(contains ammonium hydroxide) soaked rags to help cope with Chlorine gas, although im not sure of its effectiveness.

[atomophile]

A potential prophylactic treatment of sodium bicarbonate-sodium chloride aerosol has been suggested, at least for NOx exposure. Inhalation of compounds containing -SH or -S-S- groups has also been proposed for NOx, and with the mention of cystine in a previous post, a correlation between the NOx treatments and PFIB treatments may be drawn. a-Tocopherol has been suggested also. And prednisone used later, when you're really in deep shit- entering the drowning pool.

[MrSamosa]

BBC Online had an interesting article about frying pan fumes... http://news.bbc.co.uk/2/hi/science/nature/3441255.stm

Here's what caught my attention:

"These toxic compounds, which contaminate a wide range of animals, can cause severe health disorders such as cancer, damage to the immune system, behavioural problems, hormone disruption, or even feminisation."

Feminisation... :D

[simply RED]

Where can I find the RTPB "rules"?
writing here not to make too much posts:

What is UTFSE?

[NightStalker]

Try UTFSE.

I've been told it can work miracles. :rolleyes:

Might even pull up a thread where they're attached for all your downloading pleasure! :p

[MrSamosa]

UTFSE = "Use The F*cking Search Engine," if I'm not mistaken, and it's not a nice thing to say to experience forumites.

I downloaded the RTPBs (Rules To Profit By) some time ago from the FTP server, though I never got it to open (never felt like looking up how to fix the problem). I don't know if it's still there, as I haven't been on it in a long time...though I imagine it still would be.

Back on topic now eh?

[SteveHit]

I actually made a reasonable quantity (20 g) of PFIB when I was a research student (a long time ago). However, preparation from teflon was not considered to be efficient, and I made PFIB by flow pyrolysis of perfluoropropene (CF3CF=CF2) at 800 C, which afforded a 42 % yield.

I was given many warnings about handling the PFIB, including the story of several Russian workers being killed by it when some leaked in a laboratory accident... as a result it had to be prepared and handled in a lab equipped with high velocity fume cupboards, and I had to wear breathing apparatus throughout, while being observed through the lab window by a nurse, just in case!

The PFIB was handled in a vacuum line, with liquid nitrogen traps to prevent any losses, and was purified by low temp distillation.

Overall, it's nasty stuff and, being very volatile, I wouldn't like to prepare it without taking exceptional safety precautions.

[simply RED]

Not PFIB but another fluorine compound with 0,1 - 0,2 g lethal dose
http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?rxntypeid=275&prep=CV4P0525

[nbk2000]

Basic toxic fluoride chemistry is covered by several books on the FTP.