Things I Won’t Work With: Dimethylcadmium (2013) | Hacker News Reader

Things I Won’t Work With: Dimethylcadmium (2013)

blogs.sciencemag.org

119 pointsdjoldman26 comments

These are always a delight to read. Check out the whole series here:

http://blogs.sciencemag.org/pipeline/archives/category/thing...

Sand Won't Save You This Time (the prequel to Chlorine Trifluoride: Some Empirical Findings) is also worth the read. Quoting John Drury Clark:

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.

http://blogs.sciencemag.org/pipeline/archives/2008/02/26/san...

Worth the read for me.

I Googled the ISBN of the quoted book by Clark "Ignition" and found a PDF copy online.

http://library.sciencemadness.org/library/books/ignition.pdf

There was some discussion when that PDF was posted here 3 weeks ago: https://news.ycombinator.com/item?id=10683778

His follow-up from 2013 includes video of what actually happens when you pour this substance on various types of protective gear. It really drives his point home (and is full of entertaining explosions).

http://blogs.sciencemag.org/pipeline/archives/2013/04/05/chl...

That's nothing. Resublimated Thiotimoline dissolves before it hits the water. Look here:

https://en.wikipedia.org/wiki/Thiotimoline

How about azidoazide azide or 1-diazidocarbamoyl-5-azidotetrazole (C2N14)?

It will "literally explode if you move it, touch it, disperse it in solution, expose it to x-rays, expose it to light, and even if you did absolutely nothing to it." [1]

[1] http://pipeline.corante.com/archives/2013/01/09/things_i_won...

it's not chemistry, but tangentially, I have another amazing read.

Liquid N2 is held in a dewar, consisting of an internal and an external tank with vacuum in between. In case of overpressure, there are blowout valves, designed to relieve pressure in a large hole rather than a small one. You'd rather have a large hole because a high pressure tank with a small hole is basically a rocket. Or a grenade. Also, the N2 liquid to gas expansion factor is roughly 1:700.

In any case, some special person at Texas A&M noticed a N2 dewar with a presumably damaged overpressure blowout valve and fucking welded a brass plug in place. Eventually, the tank catastrophically failed, most likely due to corrosion of the internal tank, leading to temperature increase and the aforementioned 1:700 volume increase. According to I believe the tank manufacturer, the tank mechanically fails at 1200 psi. When it finally went boom, it shredded the room it was in, put a 24-in hole through a concrete floor, significantly damaged a concrete/steel support beam, and was eventually stopped by a 3-in water main and other stuff in a mechanical room. Miraculously it went at 3-am or so and no-one was present.

When people determined what had happened, some unlucky dude who didn't get paid nearly enough got to frantically inspect every tank in the chemistry building to see if the mystery welder had "upgraded" any others.

There's a report pdf somewhere on the internet that I can't find at the moment.

I may have some details wrong but the boom part is definitely right =P

edit: https://web.archive.org/web/20060901094515/http://finance.ta...

it's worth looking at the pictures in the pdf

I think there should be a category of "there I fixed it" just for over zealous welders. I worked with a robot that had an aluminum tool that got mangled every time the robot got in a fight with the lift table. This was a Kuka 450 (as in kg), and it could really stack. A maintenance guy thought it was an enormous chore rebuilding the tool each time, so he bolted (literally) a 3/8 inch steel plate to the thin aluminum a frame. And when that tore welded the whole shebang. Next time the robot snapped its wrist, since the tool could no longer buckle and absorb the impact, and it rather impressed the service engineer with the... sturdiness of the tool.

I wanted to share the story about environmental's efforts to put gas meters on the safety release valves on our large liquid argon dewars, but we thankfully convinced them that accidentally blowing a crater in the plant was a worse OSHA violation than upsetting our local regulators. (An accident in a nearby county with a truck hauling liquid gas dewars resulted in a death by displacing all the air in the intersection with Argon, leading the inert gas to be classified as a dangerous controlled substance that needed to be monitored and metered...)

Oh, I have a story about LN as well. I studied nuclear engineering in school and our department had a nuclear reactor in the building (important in a moment). Nuclear engineering labs usually have large LN tanks because some types of radiation detector require cryogenic cooling. One day of the week at about 3AM some [presumably students living on campus[ were walking by and heard the tanks venting exactly as you mentioned. They called it in to campus security, who panicked and assumed the reactor was melting down (not even possible with this reactor) and by 3:30 AM a full emergency response crew, in full HAZMAT gear and complete with heavy vehicles has surrounded the building only to discover that nothing is remotely wrong.

I'm surprised a 3" water main stopped it, pipes in general are typically made of very soft, low quality steel. It probably just ran out of energy after flying through everything else.

The plug wasn't welded, it simply screwed into existing pipe threads replacing an overpressure valve.

"It struck two 3 inch water mains and drove them and the electrical wiring above them into the concrete roof of the building, cracking it."

=> that concrete roof probably had more to do with the stopping than the pipes below it.

I handle vapors of organometallic compounds everyday. dimethyl-X, trimethyl-X, tetramethyl-X and other long name OM compounds that can kill slowly or instantly. Recently theres HF vapors and today its a cyanide compound.

I'm lucky to still be alive!

1) Why do you have to handle these compounds every day? (if it's for work, what sort of work (oh, and are you well compensated)? if it's for research, research on what? if it's for fun, why?)

2) What sort of personal protective gear do you have to use?

1) I'm a grad student working on MOCVD and ALD, so no I'm not well compensated :(

2) Not enough. Respirator, coats and gloves.

That was an entertaining read. The comments are worth it as brief glimpses into the wild west of consumer chemicals. I'm glad most of the toxic exotic compounds in my life are safely held within a laptop's plastic casing.

Enjoyable read! My mum is a painter and was recently involved in a campaign against new cadmium regulation in the UK. It's used to produce a red paint that apparently has no substitute. They argued that since it's very expensive, little of it ends up in drains. I'm pleased to say the regulation went through anyway, but with an exception for oil paints.

In grad school around 1980 I was doing some reaction under a hood using DMSO as the solvent and for some reason it was converted into DMS (DiMethyl Sulfide) and we discovered how bad the vent system was in the building (it was terrible). The building was evacuated and they forced me to go back in to look up how toxic DMS was (stupid grad students are expendable). Thankfully while it is chemical related to Hydrogen Sulfide it was not all that dangerous and in a couple of hours it cleared. However if you ever get to smell it you will run as far as you can and the odor is unstoppable. Forget tear gas, toss some of this into a building and watch everything run out. Cleaning out the hood was a terrible experience.

... I think I'm going to go through my basement and make sure I don't have any old nicad batteries kicking around now.

While cadmium is toxic, organometallic compounds are much worse than what you have in your batteries.

For example, you can play with mercury. You definitely SHOULD NOT, but it won't kill you. On the other hand, dimethyl mercury WILL kill you.

When talking about the toxicity of dimethylmercury, it is almost obligatory to mention https://en.wikipedia.org/wiki/Karen_Wetterhahn

exposure to only a few drops of the chemical absorbed through the gloves proved to be fatal after less than a year.

wow. Apparently nobody thought to see if it goes through latex gloves, and it apparently does in seconds! Current safety protocol is now "highly resistant, flexible, plastic-laminate gloves [...]. For increased protection, such thin gloves can be worn under long-cuffed, heavy-duty outer gloves made of, for example, neoprene." Or just not using dimethylmercury.

"Her husband saw tears rolling down her face. I asked if she was in pain. The doctors said it didn't appear that her brain could even register pain."[5]

Presumably the body more readily incorporates organometallics than elemental metal

Do you know why?

The body is working with organic molecules more easily. You can literally drink mercury and chew iron and nothing bad will happen (you can, but you shouldn't) - you will pass it the next day. We humans cannot absorb non organic molecules easily. A starving person won't be able to eat charcoal. The mercury vapors are dangerous because you breathe them in which is easy. Organic compound with mercury can be absorbed trough the digestive tract - and mercury inside the blood stream is big problem.

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