5 ms·

There was this amazing article in 2010 about "chemical compounds i will not work with". Tetrafluorohydrazine was one of them: https://blogs.sciencemag.org/pipe

by f2f 7y ago

There was this amazing article in 2010 about "chemical compounds i will not work with". Tetrafluorohydrazine was one of them: https://blogs.sciencemag.org/pipeline/archives/2010/02/23/things_i_wont_work_with_dioxygen_difluoride https://blogs.sciencemag.org/pipeline/archives/2010/02/23/th... and mentions briefly that hydrazine is produced at los alamos for national security purposes.

saagarjha 7y ago
I don’t see a mention of hydrazine in the link you shared.
- wolf550e 7y ago
  People ask why the people servicing it after landing (in the photos) are in hazmat suits. It's because of the hydrazine and N2O4.
- mattnewport 7y ago
  Yeah, it's an amusing article but it's not about Tetrafluorohydrazine and there don't seem to be any others in the series that are. Tetrafluorohydrazine also doesn't seem to be the same thing as hydrazine which is used as a fuel in some spacecraft. The article does mention tetrafluorohydrazine being added to FOOF which is the actual subject of the article and a comment mentions tetrafluorohydrazine being used as an oxidizer for rocket fuels.
- f2f 7y ago
  the article mentions hexafluoride. but LANL did (and probably still does) hydrazine. source: https://patents.google.com/patent/US2690378 https://patents.google.com/patent/US2690378 (used to intern, and subsequently work there, although not as a chemist, of course. i'm not that smart) and if you want to pedant that the patent wasn't issued to los alamos nat'l laboratory... well, in '54 things were different :)
wolf550e 7y ago
Almost all spacecraft (including satellites) use hydrazine (MMH, UDMH or Aerozine 50) for rotating around itself to keep pointing in the right direction (see attitude control, reaction control system). When used as a bi-propellant, hydrazine is usually combined with N2O4, which is also super toxic. It is not just the military that uses these things. Everyone uses it because it is the best performing high thrust (not ion engine) non-cryogenic (storable) propellant. It being hypergolic (self igniting) is a bonus for reliability. The military actually switched to solids for ICBMs and SLBMs. The F-16 has a hydrazine APU, and I would not be surprised if the F-35 does the same thing.
- agurk 7y ago
  > The F-16 has a hydrazine APU, and I would not be surprised if the F-35 does the same thing. The F-16 has an EPU not an APU, i.e. an Emergency Power Unit vs an Axillary Power Unit. Lacking an APU is an exception when it comes to jet aircraft and necessitates a few changes. Relevant here is that an APU can provide power in an emergency, so the role is played by the hydrazine powered EPU for the F-16. This makes hydrazine somewhat more of a rational choice for something you expect to use rarely. If it were expected to be frequently used then it would have to be frequently refilled and that would necessitate all ground crew wearing the full body hazmat suits you see in the photo for the X-37b here as well as many other complex safety precautions. The F-35 has a conventionally jet fuelled APU[0] so it has no need for an EPU or hydrazine. Interestingly Concord didn't have space for an APU (due to the shape of the empennage and placement of a rear fuel tank). I have seen pictures of a hydrazine powered EPU on one of the prototypes, but this was never going to make it into service as certifying carrying something as toxic as hydrazine - even back then - would be nigh on impossible. This is the question that starts the most epic thread about Concord[1] (warning - you may get sucked into reading all 103 pages!) [0] http://www.f-16.net/forum/viewtopic.php?f=60&t=12192 http://www.f-16.net/forum/viewtopic.php?f=60&t=12192 [1] https://www.pprune.org/tech-log/423988-concorde-question.html https://www.pprune.org/tech-log/423988-concorde-question.htm...
  - foobarian 7y ago
    Re: Concorde forum link: what a treasure trove of information!
dghughes 7y ago
>There was this amazing article in 2010 about "chemical compounds i will not work with". Tetrafluorohydrazine was one of them: I remember reading that article it was interesting. But it's funny that hydrofluoric acid (HF) was not mentioned since it seems to be incredibly dangerous. Periodic Videos on Youtube has a new video about hydrofluoric acid. Professor Martyn Poliakoff mentions HF is feared by people working in chemistry. He also said that even a small drop of HF on skin will cause a heart attack (and eat through your skin). https://www.youtube.com/watch?v=6ZBwluyR2Tc https://www.youtube.com/watch?v=6ZBwluyR2Tc
- ncmncm 7y ago
  Yet, you can buy it in 1% solution at your neighborhood hardware store. Concentration matters.
  - dghughes 7y ago
    The fun part in the video is when they neutralized the HF with sodium carbonate to make sodium fluoride which is used in toothpaste. Keeping in mind the concentration again.
  - ls612 7y ago
    Dumb question from someone who knows very little chemistry; is it possible for a malicious actor to use some sort of distillation process to take that 1% solution and concentrate it into something much more dangerous?
    - NickNameNick 7y ago
      It's probably going to be more dangerous to the amature chemist than thier intended victim.
    - dsfyu404ed 7y ago
      Yes but it's way cheaper and easier to just use drain cleaner for those kinds of malicious things.
  - 7y ago
jchw 7y ago
It’s actually a series of articles: https://blogs.sciencemag.org/pipeline/archives/category/things-i-wont-work-with https://blogs.sciencemag.org/pipeline/archives/category/thin...
philwelch 7y ago
One of the near misses in terms of potentially fatal spacecraft accidents involved fumes from hydrazine and dinitrogen tetroxide entering the cockpit of the Apollo capsule returning from the Apollo-Soyuz docking in 1975. The astronauts survived after two weeks of hospitalization, thankfully.
Balgair 7y ago
Dr. Lowe's Things I Won’t Work With is on the top 10 best blogs out there. What an utter joy! His writing style is a breath of fresh air for the sleepy journal-club style articles. He is funny, informative, and interesting. A great addition to the world of science advocates. I love his blog. Some favs: Can’t Stop the Nitro Groups :"... this new paper’s introduction includes the phrase “In our continuing efforts to introduce as many nitro groups associated with a tetrazole ring as possible. . .” and to most organic chemists that’s roughly equivalent to saying something like “In our continuing efforts to spray as much graffiti on the snouts of salt-water crocodiles as possible. . .”[0] Sand Won't Save You This Time: "It is, of course, extremely toxic, but that’s the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively."[1] Hexanitrohexaazaisowurtzitane: "Hexanitro? Say what? I’d call for all the chemists who’ve ever worked with a hexanitro compound to raise their hands, but that might be assuming too much about the limb-to-chemist ratio." [2] Dioxygen Difluoride (aka FOOF, aka "Satan's Kimchi")[3] [0]https://blogs.sciencemag.org/pipeline/archives/2019/08/15/cant-stop-the-nitro-groups https://blogs.sciencemag.org/pipeline/archives/2019/08/15/ca... [1] https://blogs.sciencemag.org/pipeline/archives/2008/02/26/sand_wont_save_you_this_time https://blogs.sciencemag.org/pipeline/archives/2008/02/26/sa... [2] https://blogs.sciencemag.org/pipeline/archives/2011/11/11/things_i_wont_work_with_hexanitrohexaazaisowurtzitane https://blogs.sciencemag.org/pipeline/archives/2011/11/11/th... [3] https://blogs.sciencemag.org/pipeline/archives/2010/02/23/things_i_wont_work_with_dioxygen_difluoride https://blogs.sciencemag.org/pipeline/archives/2010/02/23/th...
Symmetry 7y ago
There's been some work recently on using Hydroxylammonium nitrate (HAN) as a less toxic and better performing replacement for Hydrazine. https://en.wikipedia.org/wiki/Hydroxylammonium_nitrate https://en.wikipedia.org/wiki/Hydroxylammonium_nitrate https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19960048008.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/199600...

by f2f 7y ago

saagarjha 7y ago

I don’t see a mention of hydrazine in the link you shared.

wolf550e 7y ago
People ask why the people servicing it after landing (in the photos) are in hazmat suits. It's because of the hydrazine and N2O4.
mattnewport 7y ago
Yeah, it's an amusing article but it's not about Tetrafluorohydrazine and there don't seem to be any others in the series that are. Tetrafluorohydrazine also doesn't seem to be the same thing as hydrazine which is used as a fuel in some spacecraft. The article does mention tetrafluorohydrazine being added to FOOF which is the actual subject of the article and a comment mentions tetrafluorohydrazine being used as an oxidizer for rocket fuels.
f2f 7y ago
the article mentions hexafluoride. but LANL did (and probably still does) hydrazine. source: https://patents.google.com/patent/US2690378 https://patents.google.com/patent/US2690378 (used to intern, and subsequently work there, although not as a chemist, of course. i'm not that smart) and if you want to pedant that the patent wasn't issued to los alamos nat'l laboratory... well, in '54 things were different :)

wolf550e 7y ago

Almost all spacecraft (including satellites) use hydrazine (MMH, UDMH or Aerozine 50) for rotating around itself to keep pointing in the right direction (see attitude control, reaction control system). When used as a bi-propellant, hydrazine is usually combined with N2O4, which is also super toxic. It is not just the military that uses these things. Everyone uses it because it is the best performing high thrust (not ion engine) non-cryogenic (storable) propellant. It being hypergolic (self igniting) is a bonus for reliability. The military actually switched to solids for ICBMs and SLBMs. The F-16 has a hydrazine APU, and I would not be surprised if the F-35 does the same thing.

agurk 7y ago
> The F-16 has a hydrazine APU, and I would not be surprised if the F-35 does the same thing. The F-16 has an EPU not an APU, i.e. an Emergency Power Unit vs an Axillary Power Unit. Lacking an APU is an exception when it comes to jet aircraft and necessitates a few changes. Relevant here is that an APU can provide power in an emergency, so the role is played by the hydrazine powered EPU for the F-16. This makes hydrazine somewhat more of a rational choice for something you expect to use rarely. If it were expected to be frequently used then it would have to be frequently refilled and that would necessitate all ground crew wearing the full body hazmat suits you see in the photo for the X-37b here as well as many other complex safety precautions. The F-35 has a conventionally jet fuelled APU[0] so it has no need for an EPU or hydrazine. Interestingly Concord didn't have space for an APU (due to the shape of the empennage and placement of a rear fuel tank). I have seen pictures of a hydrazine powered EPU on one of the prototypes, but this was never going to make it into service as certifying carrying something as toxic as hydrazine - even back then - would be nigh on impossible. This is the question that starts the most epic thread about Concord[1] (warning - you may get sucked into reading all 103 pages!) [0] http://www.f-16.net/forum/viewtopic.php?f=60&t=12192 http://www.f-16.net/forum/viewtopic.php?f=60&t=12192 [1] https://www.pprune.org/tech-log/423988-concorde-question.html https://www.pprune.org/tech-log/423988-concorde-question.htm...
- foobarian 7y ago
  Re: Concorde forum link: what a treasure trove of information!

dghughes 7y ago

>There was this amazing article in 2010 about "chemical compounds i will not work with". Tetrafluorohydrazine was one of them: I remember reading that article it was interesting. But it's funny that hydrofluoric acid (HF) was not mentioned since it seems to be incredibly dangerous. Periodic Videos on Youtube has a new video about hydrofluoric acid. Professor Martyn Poliakoff mentions HF is feared by people working in chemistry. He also said that even a small drop of HF on skin will cause a heart attack (and eat through your skin). https://www.youtube.com/watch?v=6ZBwluyR2Tc https://www.youtube.com/watch?v=6ZBwluyR2Tc

ncmncm 7y ago
Yet, you can buy it in 1% solution at your neighborhood hardware store. Concentration matters.
- dghughes 7y ago
  The fun part in the video is when they neutralized the HF with sodium carbonate to make sodium fluoride which is used in toothpaste. Keeping in mind the concentration again.
- ls612 7y ago
  Dumb question from someone who knows very little chemistry; is it possible for a malicious actor to use some sort of distillation process to take that 1% solution and concentrate it into something much more dangerous?
  - NickNameNick 7y ago
    It's probably going to be more dangerous to the amature chemist than thier intended victim.
  - dsfyu404ed 7y ago
    Yes but it's way cheaper and easier to just use drain cleaner for those kinds of malicious things.
- 7y ago

jchw 7y ago

It’s actually a series of articles: https://blogs.sciencemag.org/pipeline/archives/category/things-i-wont-work-with https://blogs.sciencemag.org/pipeline/archives/category/thin...

philwelch 7y ago

One of the near misses in terms of potentially fatal spacecraft accidents involved fumes from hydrazine and dinitrogen tetroxide entering the cockpit of the Apollo capsule returning from the Apollo-Soyuz docking in 1975. The astronauts survived after two weeks of hospitalization, thankfully.

Balgair 7y ago

Dr. Lowe's Things I Won’t Work With is on the top 10 best blogs out there. What an utter joy! His writing style is a breath of fresh air for the sleepy journal-club style articles. He is funny, informative, and interesting. A great addition to the world of science advocates. I love his blog. Some favs: Can’t Stop the Nitro Groups :"... this new paper’s introduction includes the phrase “In our continuing efforts to introduce as many nitro groups associated with a tetrazole ring as possible. . .” and to most organic chemists that’s roughly equivalent to saying something like “In our continuing efforts to spray as much graffiti on the snouts of salt-water crocodiles as possible. . .”[0] Sand Won't Save You This Time: "It is, of course, extremely toxic, but that’s the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively."[1] Hexanitrohexaazaisowurtzitane: "Hexanitro? Say what? I’d call for all the chemists who’ve ever worked with a hexanitro compound to raise their hands, but that might be assuming too much about the limb-to-chemist ratio." [2] Dioxygen Difluoride (aka FOOF, aka "Satan's Kimchi")[3] [0]https://blogs.sciencemag.org/pipeline/archives/2019/08/15/cant-stop-the-nitro-groups https://blogs.sciencemag.org/pipeline/archives/2019/08/15/ca... [1] https://blogs.sciencemag.org/pipeline/archives/2008/02/26/sand_wont_save_you_this_time https://blogs.sciencemag.org/pipeline/archives/2008/02/26/sa... [2] https://blogs.sciencemag.org/pipeline/archives/2011/11/11/things_i_wont_work_with_hexanitrohexaazaisowurtzitane https://blogs.sciencemag.org/pipeline/archives/2011/11/11/th... [3] https://blogs.sciencemag.org/pipeline/archives/2010/02/23/things_i_wont_work_with_dioxygen_difluoride https://blogs.sciencemag.org/pipeline/archives/2010/02/23/th...

Symmetry 7y ago

There's been some work recently on using Hydroxylammonium nitrate (HAN) as a less toxic and better performing replacement for Hydrazine. https://en.wikipedia.org/wiki/Hydroxylammonium_nitrate https://en.wikipedia.org/wiki/Hydroxylammonium_nitrate https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19960048008.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/199600...