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Comment by manarth | Hacker News Reader

Other "sources" (using the word loosely as their provenance is unclear)

  > "based on the information available, this was a localized issue with only one student directly exposed. Their reported use of dimethyl mercury was unauthorized. MIT does not allow the purchase or synthesis of dimethyl mercury." [1]

Karen Wetterhahn's exposure and death [3] is a cautionary tale of the extreme toxicity of dimethyl mercury, and was instrumental in new safety recommendations, including strongly discouraging the use of dimethyl mercury for any purpose.

[1] https://www.reddit.com/r/mit/comments/1w12gb9/dimethyl_mercu...

[2] https://www.nbcboston.com/news/local/hazmat-crews-respond-to...

[3] https://en.wikipedia.org/wiki/Karen_Wetterhahn

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Yes, dimethyl mercury is terrifying stuff - it killed Karen Wetterhahn from a few drops that went _through_ the gloves she had on:

> The case proved that the standard precautions at the time, all of which Wetterhahn had carefully followed, were inadequate for "super-toxic" chemicals like dimethylmercury

(from the Wikipedia page [3])

Methyl any sort of metal - especially heavy metals - are probably not something you want to splash on like aftershave.

There aren't really any "good" organometals, but if there were, they wouldn't be this stuff.

Sufficiently pure dichloromethane is also fun stuff. It just eats through most any gloves, plastics, whatever. Even PET, and only polyethylene is somewhat resistant.

LD50 about 2mg/kg oral. By oral it's meant that well.. if you soak your hands in it it will be worse.

Still it's the goto thinner for f/ex gluing ABS. I have a couple liters sitting on the shelf right beside me.

> Less than 0.1 mL is capable of inducing severe mercury poisoning resulting in death

Holy hell. I would've have believed it was possible for a non-biological substance to be so toxic.

The density of Dimethyl Mercury is almost 3g/ml, so 0.1 mL is like 300 mg.

From https://en.wikipedia.org/wiki/Cyanide_poisoning

> A fatal dose for humans is on average 1.52 mg/kg of body weight

Assuming 80kg(175pounds), that's like 120mg of Cyanide.

There is probably even more nasty stuff.

well, easily. any organophosphorus stuff for example.

Actually organophosphates are not that lethal. See the LD50 of this example: https://en.wikipedia.org/wiki/Malathion

You may also be thinking of phosgene, which actually contains no phosphorous at all. But it is extremely toxic see the LC50: https://en.wikipedia.org/wiki/Phosgene

This is not true, and choosing the LD50 of Melathion to represent organophosphates as a whole seems odd. He was probably thinking of nerve agents or perhaps pesticides. Take a look at the LD50's of the former. These are among the nastiest, most lethal substances known to man.

Yes. See for example any number of nerve agents such as VX. https://en.wikipedia.org/wiki/VX_(nerve_agent). Yes, you can quibble over whether they count as "phosphates" given they often have fluoryl or other substituents, but the class is generally referred to as organophosphates, and they certainly have phosphorous in them. Malathion, is also an organophosphate which acts via the same pathway, but only in insects.

If you're worried about >100mg (0.1ml) then, don't think about the dosages people use for botox! It's 1x,2x,3x 80picograms per injection.

I guess it's a biological product, but it's certainly not "living".

Then there's carfentanil and similar which are deadly only at much higher 100 microgram levels.

the methyl groups make it organic chemistry (and dangerous), elemental mercury is fairly safe

There was a time not so long ago when it was common for chemistry teachers to show off pools of mercury in their bare hands.

By the time I first took chemistry classes, though, that practice had stopped, less out of concern of exposure to liquid mercury and more for accidental exposure to gaseous forms due to spills.

When I was in highschool in the 1960s mercury in the chemistry lab was commonplace.

One way to familiarize students with mercury was to have several liters of it in a wide open-top jar and have them force their fist through the mercury pool to the bottom of the jar.

In fact, forcing one's hand through mercury between six to eight inches deep is not easy, some kids found it too difficult to do.

I'd describe my hand as feeling very squeezed and it being forced upwards to the surface with considerable force. The experience was certainly unforgettable.

There were some safety protocols: good ventilation (to minimize Hg vapor) and afterwards hands had to be thoroughly scrubbed with soap and water.

Good video about what happened to her body: https://www.youtube.com/watch?v=NJ7M01jV058

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