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Other "sources" (using the word loosely as their provenance is unclear) > "based on the information available, this was a localized issue with only one stude

by manarth 19d ago

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_mercury_poisoning/ https://www.reddit.com/r/mit/comments/1w12gb9/dimethyl_mercu... [2] https://www.nbcboston.com/news/local/hazmat-crews-respond-to-chemical-exposure-incident-at-mass-general-hospital/4004680/ https://www.nbcboston.com/news/local/hazmat-crews-respond-to... [3] https://en.wikipedia.org/wiki/Karen_Wetterhahn https://en.wikipedia.org/wiki/Karen_Wetterhahn

gilleain 19d ago
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])
- ErroneousBosh 16d ago
  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.
- lstodd 16d ago
  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.
randerson 17d ago
Good video about what happened to her body: https://www.youtube.com/watch?v=NJ7M01jV058 https://www.youtube.com/watch?v=NJ7M01jV058
recursivecaveat 17d ago
> 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.
- gus_massa 17d ago
  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 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.
  - lstodd 17d ago
    well, easily. any organophosphorus stuff for example.
    - jackyinger 16d ago
      Actually organophosphates are not that lethal. See the LD50 of this example: https://en.wikipedia.org/wiki/Malathion 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 https://en.wikipedia.org/wiki/Phosgene
      - chorsestudios 16d ago
        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.
        ethanj8011 16d ago
        Yes. See for example any number of nerve agents such as VX. https://en.wikipedia.org/wiki/VX_(nerve_agent) 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.

by manarth 19d ago

gilleain 19d ago

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])

ErroneousBosh 16d ago
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.
lstodd 16d ago
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.

randerson 17d ago

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

recursivecaveat 17d ago

> 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.

gus_massa 17d ago
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 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.
- lstodd 17d ago
  well, easily. any organophosphorus stuff for example.
  - jackyinger 16d ago
    Actually organophosphates are not that lethal. See the LD50 of this example: https://en.wikipedia.org/wiki/Malathion 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 https://en.wikipedia.org/wiki/Phosgene
    - chorsestudios 16d ago
      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.
      - ethanj8011 16d ago
        Yes. See for example any number of nerve agents such as VX. https://en.wikipedia.org/wiki/VX_(nerve_agent) 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.