Hydrofluoric Acid: An Invisible Fire (1996) | Hacker News Reader

Hydrofluoric Acid: An Invisible Fire (1996)

discovermagazine.com

132 pointsDEFCON2862 comments

Every time I hear anything about Flourine, I’m reminded of “Sand Won’t Save You This Time” http://blogs.sciencemag.org/pipeline/archives/2008/02/26/san...

I also suggest watching the Periodic Table of Videos episode on Flourine: https://youtu.be/vtWp45Eewtw

A link to "things I won't work with"? Well there goes my entire day!

Despite failing chemistry in high school (and never looking at it again afterward), I loved Derek Lowe's "Things I Won't Work With" column.

He did an excellent job of describing some truly terrifying chemical substances in a lighthearted and engaging way.

http://blogs.sciencemag.org/pipeline/?s=things+I+won%27t+wor...

Cody's Lab is also a very accessable series where the guy somewhat casually handles various acids to dissolve gold and such. He's got a series showing various ways to extract gold from other metals (or more commonly, the other metals from gold). Just in his home, maybe with an amateur extractor.

The best part is perhaps the quote at the end from Ignition!.

The book Ignition!, mentioned in the article/comments, is soon back to print[0]. After reading these articles I think the book is a must read. Too bad the Kindle version is quite bad quality.

[0] https://www.amazon.com/Ignition-Informal-History-Liquid-Prop...

Thank you very much for that, I've now swapped my pre-order to paper after reading some of the kindle reviews.

>Ignition!

FOOF

There is a great rundown of the history of fluorine by Isaac Asimov in _Galileo's Commandment: 2,500 Years of Great Science Writing_ (it might be excerpted from his book _The Noble Gases_, I'm not sure. I couldn't find an online version of the text)

(the reason I think it may be in The Noble Gases is because he talks about the creation of Xenon Tetrafluoride)

It reminded me of this gem from the same author -- http://blogs.sciencemag.org/pipeline/archives/2010/02/23/thi...

The story I remember most vividly was the researcher, Dr Karen Wetterhahn, who despite taking great care spilled one or two drops of dimethylmercury on her latex glove. The glove would prove to be no protection at all - tests later showed the dimethylmercury would have seeped through her glove and skin in less than twenty seconds. Karen began displaying the neurological symptons of mercury poisoning some three months later when it was too late to do anything. She was dead within the year.

Dimethylmercury and hydrofluoric acid are both mentioned in this list of "10 Ridiculously Dangerous Chemicals", https://listverse.com/2016/12/09/10-ridiculously-dangerous-c....

This video covers that story rather well: https://www.youtube.com/watch?v=NJ7M01jV058

It's kind of scary how easy it is to make too; much easier than e.g. sarin and almost as toxic.

HF is extremely scary, the safety precautions taken to work with it at an acid bench really bring this home.

I heard a story once of a student putting a bottle into his backpack and cycling across the city to another university building to use it in another lab. The mind boggles at the stupidity.

When I was in high school in chemistry class I accidentally picked the wrong bottle of sulphuric acid to use in an experiment - I remember thinking "this stuff actually seems to be viscous" and "why is everything getting so hot" before the explanation dawned on me....

I used HF to clean the surface of a copper scattering cell (block of copper with an internal chamber and some access ports, about 5 inches high and 4 across).

Burn cream on hands, two pairs of gloves, one silk one leather, leather apron and splash goggles. Comes packed in a plastic container which is secured to a small wooden pallette with the bottle held upright in a box with wooden batterns. Impressive warning signs.

OA has solved the mystery of why we had to use these precautions!

So why the hell was it sold as a commercial rust remover product?

Key word is "commercial". The commercial world is full of dangerous substances (when you leave the safety of an office and go into the dirty world of production :-)), out of necessity, but you are assumed to have received proper training and be in possession of proper safety equipment.

Concentration has a lot to do with it. More dilute solutions of HF may cause burns, but t it's unlikely to kill you.

Concentrated HF is another beast entirely.

And given that it was in an old dusty bottle packed away deep, it may have concentrated over time due to evaporation.

Acids tends to pull moisture from the air (hydroscopic) and dilute rather than lose water and concentrate.

I'm guessing it came from "another era" where you could buy stuff like this without an issue?

But even few years ago I visited a wolfram mine in Portugal on a job, and was told by the guy I worked with at the time that the miners are using stuff "banned long time ago in UK" to clean the tips of the guiding ropes which we were replacing. I was never told what it was, but nowadays I suspect it was HF.

For those who might be confused, "wolfram" refers to Tungsten.

"Commercial" just implies commerce; that it was a product that could be purchased. It was not a consumer product. In the article it says the title was "Industrial Laundry Rust Remover".

There are certainly much nastier chemicals used that this in industry. As an example, I'm reminded of a quote by Gordon Moore about Intel having melted their sewer pipe, in this article:

https://www.bloomberg.com/news/features/2017-06-15/american-...

It is indeed scary. I once had to use a mixture of boiling nitric, hydrofluoric and perchloric acids... quite possibly the nastiest stuff I've ever come across, and partly responsible for my sideways move into programming.

The lab had a shower cubicle in the corner, with a tank on top and pull handle. The idea was that if you got any on you, taking an immediate shower in caustic soda was the best thing to do...

When I was a school kid, a friend and I were into blowing stuff up and general chemical mayhem (those innocent pre-9/11 days!). We used to synthesize fuming nitric acid and mix it with oleum and potassium permanganate. The resulting fuming, purple mix would cause pretty much anything it came into contact with to immediately combust.

But that sounds - if you'll pardon the pun - like child's play compared to your boiling(!) nitric, HF and perchloric acid. I cannot image how you'd even contain such an evil substance? And what was it used for?

We mixed it fresh every day, and to contain it we used crucibles made from a platinum/gold alloy. Which, needless to say, were locked away very carefully at the end of the day.

And I was using it to dissolve up rock specimens for analysis: basaltic lavas that contained chromite and other notably insoluble minerals.

That stuff would dissolve anything...

One of the labs where I first had those (also chip fabs have them) attached to a high flow water supply - normally triggered by standing inside them.

Our top H&S guy decided that as he was responsible he should be the one to test it he did cheat a bit by wearing swimming goggles to protect his eyes. He commented it was like being sand blasted with small ball bearings and "fracking hurt"

A long time ago (late 70's) a lab I worked next to had an emergency shower over each worker and there were straps on their wrists. If they jerked their arm back the shower would go off.

I want to point out from professional experience that the dangers of HF as stated in this article are not embellished in any way. It is really the stuff of nightmares.

Also it's pretty insane IMO to put it in a bottle labeled 'rust remover'. That's bound to cause accidents like this with people thinking it's just any old stain-away soap.

"Invisible fire" reminded me of something which is almost completely invisible while it burns: methanol

https://www.youtube.com/watch?v=1ZEEuCHdWFA

https://www.youtube.com/watch?v=Ku7TdLeEGsQ

I was looking for a comment that mentioned this! Pit crew methanol fire is also what I first thought this article was about when I read the title!

Alcohol fires in general, for that matter - ethanol fires are also just about invisible.

It actually reminded me of the aftermath of an arc flash ( https://en.wikipedia.org/wiki/Arc_flash ) which while the original arc is visible (and may temporarily blind any that see it) the plasma that comes out after it is not and is extremely scary because it's potentially several times hotter than the surface of the sun. The linked article has a video in it that describes the results.

I have always had a huge fear of HF, but as a biologist I rarely had to work with it. The chemical that I did work a lot with that was rather nasty was phenol (carbolic acid). Splash that on you, or worse get it in your eyes, and it hurts. I luckily never got it in my eyes, but I had a few cap-failing eppendoff tubes (being vortexed) end up all over my face. Not nice.

The worst horror story I was told about phenol was of a grad student a few years before me doing a large DNA extraction using phenol in a 3 litre measuring cylinder. They filled it with phenol and DNA solution and then sealed the end using parafilm (a stretchy plastic membrane). They then mixed the solution by inverting the cylinder. You won't be surprised to learn that phenol dissolves parafilm and the phenol ran straight down the student's arm and they ran straight off to hospital.

Phenol... ah, the nostalgia. As a teenager, I once added a drop of fuming nitric acid to some phenol. I understood that I may be able to make picric acid that way. I just didn't appreciate quite how unstable the resulting compound would be until the instant the acid hit the phenol and the glass beaker disappeared in the resulting detonation. I was not wearing googles (of course), and to this day I am thankful no glass hit my eyes. I'm also extremely thankful I only added a single drop of acid. Scary substances indeed!

We had a tanker truck full of the stuff overturn a couple weeks ago in a remote area and I got a call from the hazmat guys about running a calcium gluconate line if the stuff escaped containment. (I work for the health department.) They usually use oral tape, but they were worried it wouldn't work fast enough and they couldn't get medical aid fast enough since the nearest hospital to the truck was about 80 miles away.

Fortunately they were able to right the truck without any spilling.

That one you probably _do_ want a Prop 65 notification for ...

Prop 65 doesn't apply to acute toxicity.

HF is a scary bond. I think the only other stuff that scares me more is CF3 and FOOF, the first being very very good at burning stuff that normally doesn't burn like Asbestos and Sand, the later combusting explosively when coming into contact with Water Ice at 90K.

To be honest, Flourine is a scary atom. A lot of the bonds it forms are also scary. And toxic.

That's what you get when you mix a highly electronegative element with anything else!

There was an explosion at a refinery in Superior Wi last week. The blast and resulting fire was within 200 feet of a tank that can hold 76,000 pounds of hydrogen fluoride (only 15,000 lbs were in the tank at the time).

Needless to say, officials are reconsidering the use of Hydrofluoric acid at the facility: http://www.duluthnewstribune.com/business/energy-and-mining/...

The thing I've always found most interesting about hydrofluoric acid is that it's corrosive and poisonous. Other acids like hydrochloric acid and sulfuric acid are corrosive, but they're not poisonous like hydrofluoric is. Other common acids will burn you, but that's the extent of their damage. Hydrofluoric acid will burn you and absorb into your body, interfering with calcium ions in a way that can lead to death.

This stuff is the active ingredient in glass "etching cream". Amazingly, many DIY craft videos on YouTube demonstrate it WITHOUT USING GLOVES!

Yep, I've seen these videos before and am aghast at how nonchalantly they work with nasty stuff.

Me - I use PPE when working with pretty much any solvent or etchant. And that includes gloves and goggles at a minimum. And if the stuff is not nice, I'm using a stick of sorts to apply (wood, metal, glass; whichever's less reactive).

And if I were dealing with things like HF, you can bet your ass that I'm building some sort of automated setup. HF spattering on a webcam lens means a loss of $50. HF spattering on me means I possibly will die or suffer horrendously. Same with lasers as well. Telepresence is so much safer, and failure means a few hundred dollars of equipment replacement.

Armour Etch doesn't have HF, but it does have other fluorides https://www.msdsdigital.com/armour-etch-glass-etchant-msds

That's interesting. Thanks very much for the correction, and the link!

I wonder why they were so worried about radial artery spasm. If it closes off, you still have sufficient collateral circulation via the ulnar artery. This happens not infrequently in procedures where you catheterize the radial artery.

They were worried because they thought the margin you normally have did not exist in this case, and they tried to avoid any drop in circulation, which would reduce the amount of fresh calcium brought into the hand, which might not be compensated by the additional artificial supply if the radial artery's flow dropped. In those other procedures that you mention you have a bit more room because normally the tissues are not at their limit of how much of the various molecules supplied by blood they use.

For those unfamiliar with how blood supplies various molecules, some of it solved in blood directly, some of it bound to carriers, most famous probably being oxygen: It's not like in a human supply chain where an empty truck or a train is loaded to capacity and then again emptied completely when it reaches a destination point. Instead, it's an equilibrium that changes based on things like partial pressure or acidity (pH is very slightly more basic in the lungs, slightly more acidic in the periphery, because of CO2 - also see "Bohr effect") and a lot of other variables. There is no 0% or a 100%. Here is an example for a curve for oxygen: https://courses.lumenlearning.com/wm-biology2/chapter/transp...

I'm highly familiar with details of vascular supply.

My point is that you have to weigh benefits of getting calcium there rapidly vs. potential harms of radial artery occlusion.

> I'm highly familiar with details of vascular supply.

I assumed as much, does that invalidate anything in my comment? I made it fully expecting that you have the knowledge. That's why I prefaced paragraph two with "For those unfamiliar with how blood supplies various molecules...", to avoid that you feel you are the target of a lecture about things you already know very well.

Not to mention the millions of people who don’t have a radical artery because it has been harvested to use as a coronary artery for coronary artery bypass grafts

Nowadays they usually use the internal mammary artery. But if they did harvest the RA I don't think it would be possible to inject, let alone spasm :)

That’s entirely dependent on anatomy, and if you need more than 2 grafts you will almost always take a radial, which is particularly common given the high and increasing rates of diabetes in CABG patients, which produces diffuse disease VS couple primary site blockages. Saphenous vein also a common target

Okay, but what about stannous flouride and sodium fluoride?

No one ever discusses the toothpaste fluorine ions, in conjuction with the much more terrifying acid, which is the boogey man that haunts the fears behind fluoridated water, and so on...

This is a good little interesting video on fluorine here (previously linked by someone else), and the ending is the best description of tin fluoride for teeth I've ever seen -- well worth the ~6min

https://www.youtube.com/watch?v=vtWp45Eewtw&feature=youtu.be

(edit: added link)

As someone who didn't apply themselves to Chemistry at school, what is the best way to get a decent understanding of the basics. I love the physics I can understand and would like to know more than nothing about chemistry.

You could try this: http://www.geekityourself.com/files/The-Golden-Book-Of-Chemi... it was written a bit before health and safety became and thing though.

Thanks for the suggestion. I don't fancy any practical stuff, I am dangerous enough with a soldering iron! Looks like a good resource though to get the fundamentals in, thanks!

I really enjoy Cody's Lab on YT and would like to have more background on some of the processes he undertakes.

I recommend not just any chemistry course but specifically this one:

MITx 3.091 "Introduction to Solid State Chemistry"

https://www.edx.org/course/introduction-solid-state-chemistr...

It's "archived" - good enough, everything is accessible, you just won't be able to get a "grade".

It's the gateway to "materials science" too. It is more at the edge of chemistry, towards physics and engineering. Not to mention that the teaching in this course is pretty good. Also, it is not dumbed down, you can go to MIT, take the same course and feel right at home. It's about properties of materials as a consequence of the chemical/physical properties of the components (atoms/molecules) and how they are structured (example: diamond and graphite are both made of carbon, then why are they so different).

If you want to get up to speed on "just chemistry" try Khan Academy, their explanations are pretty good and you can easily select what interests you because it is broken down into many small pieces.

Some very good suggestion there, thanks for taking the time to reply. I'd not even thought about something like the MIT course or indeed Khan Academy but looks like a good route to a better understanding.

Thanks again!

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