[HN Gopher] The Dangers of Dimethylmercury (2019)
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The Dangers of Dimethylmercury (2019)
Author : caaqil
Score : 54 points
Date : 2022-01-22 15:51 UTC (7 hours ago)
(HTM) web link (www.chemistryworld.com)
(TXT) w3m dump (www.chemistryworld.com)
| JoeyBananas wrote:
| > OSHA fined Dartmouth $9,000 (PS6890) for what it considered the
| institution's failure to provide adequate caution, particularly
| about the shortcomings of disposable latex gloves.
|
| I would think that PhD. chemists would be responsible for buying
| their own PPE. Also $9,000 is such a weirdly small number
| vmception wrote:
| And everyone's guidance was wrong at the time, so it doesnt
| make sense.
|
| OSHA used the opportunity to make a statement that wouldnt be
| fought, compared to if they tried this with a much higher fine.
| michaelcampbell wrote:
| > I would think that PhD. chemists would be responsible for
| buying their own PPE.
|
| I wouldn't; why would you?
| masklinn wrote:
| Guessing / hoping they meant the chemists would be
| responsible for determining / ordering PPE suiting what
| they're working on, not that they're supposed to pay for it
| out of pocket.
|
| Though from what I've heard about solid through sand buckets,
| and pitted face-shields, and contents of lab fridges, I'd
| think GP a bit optimistic.
| pmoriarty wrote:
| This reminds me of the tragic case (involving a different
| compound) of Sheri Sangji[1], a research assistant at UCLA who
| spilled a pyrophoric substance on her highly flammable synthetic
| sweater that she was wearing instead of a lab coat.
|
| [1] - https://en.wikipedia.org/wiki/Sheri_Sangji_case
| praptak wrote:
| This stuff is scary when you think it could be used in Putin-
| style assassinations.
| vmception wrote:
| The assassins are too scared to handle it too
|
| Coupled with the year long gap before death
|
| Its probably not an ideal choice
| pumnikol wrote:
| It is now assumed that this already happened, in 2011, in a
| Bulgarian umbrella attack in Germany's crime capital, Hanover.
| My somewhat unfounded guess is that the perpetrator himself
| perished not too long after the victim, which would explain why
| the case is still unsolved.
| trutannus wrote:
| Worked with a professor who knew this person. He talked about
| this not infrequently. All the grad students knew of the story as
| well, and would talk about it. Her death really shook up the NMR
| community. It was the reason we never use DEM in our lab, and why
| many try to avoid it at all costs even now. If I remember
| properly, and this was over 10 years ago, the reason its commonly
| used is to calibrate the spectrometers, so in some areas it gets
| hard to avoid.
|
| Also, the article mentions you need nitrile gloves to protect
| yourself from it. _This is not sufficient_ and is dangerously
| misinformed. You need _silver shield gloves_ to protect yourself
| from it.
| kibwen wrote:
| The article mentions it:
|
| _" The bulletin also urged that, aside from wearing a face
| shield, anyone working with dimethylmercury should wear Silver
| Shield laminate gloves beneath abrasion-resistant outer gloves.
| [...] Sugden points out that, when dealing with toxic
| substances, labs have shifted from latex gloves to nitrile
| gloves, which are less porous"_
| User23 wrote:
| If I were a chemist and I had to work with that satan's brew I
| wouldn't trust any gloves. I'd want a proper waldo setup.
| rotifer wrote:
| > Also, the article mentions you need nitrile gloves to protect
| yourself from it.
|
| I don't see that. With respect to an OSHA bulletin, the article
| says: The bulletin also urged that, aside from
| wearing a face shield, anyone working with dimethylmercury
| should wear Silver Shield laminate gloves beneath abrasion-
| resistant outer gloves.
|
| The mention of nitrile gloves is in a more general context:
| Sugden points out that, when dealing with toxic substances,
| labs have shifted from latex gloves to nitrile gloves, [...]
| crdrost wrote:
| Yeah I wouldn't even want nitrile gloves on with the stuff.
|
| It is worth explaining just what is wrong with it. Mercury of
| course is a toxic compound, but kids used to crack mercury
| thermometers in their mouths and suffer no consequences.
| Pressure gauges came with exposed tubs of mercury and you
| would get some on your hands and it was fine, even kind of
| fun to play around with. Felters famously felt symptoms after
| careers of using it, usually blamed on long term inhalation,
| but it required a long time and lots of exposure to get to
| that point. Many people received dental amalgams with mercury
| bases and while there has always been a conspiracy theory
| about it, it has never been acutely toxic enough to be
| mainstream--the shift to other composites has instead been
| driven by comfort (metal fillings conduct heat and cold at an
| unnatural rate) and aesthetics (the new composites are white
| instead of silvery).
|
| The basic reason is that the body does not eat metal and does
| not know what to do with it largely. Even with the metals
| that the body uses, like cobalt, it wraps every atom of
| cobalt in a big old ring of carbon and that's Vitamin B12.
|
| Dimethyl mercury, is different from normal mercury, in a
| similar way. The methyl groups are organic groups that your
| body is much more willing to absorb and process. So the latex
| is not protecting you nearly as much because latex is this
| organic natural filter that lets things through... But also
| your skin is not protecting you because this stuff can seep
| into your skin via those methyl groups, your cells are just
| like "oh you look interesting I can take you into my
| chemistry."
|
| So yeah, milligrams are all it takes, tiny trace amounts: but
| the reason that you don't think of it being quite that
| dangerous is that your exposure to the liquid metal version
| is an exposure to a form that your body is uniquely unsuited
| to process or absorb. Water off a duck's back. Even though
| the water contains neurotoxin, it just rolls right off. Even,
| in our case, when ingested. But add these little methyl
| groups, methylmercury and dimethylmercury and really any
| organic mercury molecule, it gets real bad real fast because
| it's no longer rolling off our backs, it's soaking into our
| feathers.
| aligray wrote:
| Thank you very much for taking the time to write such a
| fascinating comment!
| DaveExeter wrote:
| When I was a kid I would take the mercury from tilt-
| switches and pour it from hand to hand.
|
| So heavy and shiny!
| madengr wrote:
| phkahler wrote:
| So what is the mercury compound they put in multi-dose
| vaccines?
|
| EDIT: Thiomersal, and it looks pretty organic. I've read
| that it leaves the bloodstream quickly, but not seen solid
| evidence that its leaving the body.
| an1sotropy wrote:
| from: https://www.cdc.gov/vaccinesafety/concerns/thimeros
| al/index.... "Thimerosal contains ethylmercury, which is
| cleared from the human body more quickly than
| methylmercury, and is therefore less likely to cause any
| harm."
| pumnikol wrote:
| It's a nice step in the right direction, for sure. But,
| having worked paying jobs in both Chemistry and Product
| Safety: Not counting latex, nitrile is the bare minimum,
| really, when it comes to chemical resistivity, and it cannot
| handle heat (> 40 degC). But hot surfaces are very common in
| labs. Hands off of latex gloves, though! Not only are they no
| good against most chemicals, they can fill up like a sponge
| and soak your hands with them.
| jonpalmisc wrote:
| ChubbyEmu's video [1] on this was quite good. (As is the rest of
| his channel, if this kind of stuff interests you.)
|
| [1] https://m.youtube.com/watch?v=NJ7M01jV058
| ngcc_hk wrote:
| Whilst it becomes political now, lab accidents and lab protection
| even for known risk is still happened. If you study something
| intensively and it will leak out with more probabilities.
| supernova87a wrote:
| I think every blackboard organic chemistry class should be
| required to be taught with multiple repeated asides about the
| dangers of organometallic reagents. And other dangerous materials
| too. It's not just pushing electrons around, it's fucking with
| your life potentially.
|
| And they send you into lab with only folk-story level preparation
| if you're lucky enough to have gotten that info from others, and
| one day there is in front of you a bottle of organo-tin looking
| not too dissimilar from any other less harmful reagent. Only
| saved from danger by some slightly older grad student saying, "be
| careful around that stuff" (again, if you're lucky).
|
| I myself only knew about, for example, the dangers of ether
| bottles left for a long time, because of my own interest in
| happening to read about it. Not a single person in my entire
| undergrad/grad career mentioned it. Hydrofluoric acid. Other
| nasty stuff, etc.
|
| It's a major oversight for student education -- to be taught the
| dangers of the subject you're about to be exposed to in real
| life.
| ashtonkem wrote:
| Even as a lay person I know that most fluorine molecules are
| not to be messed with.
| dheera wrote:
| Uh, except the stuff you shove on your toothbrush?
|
| The high-dimensional surface of "threat to life" vs. molecule
| structure is super, super, non-convex.
|
| Like H2O -> yay, H2O2 -> die, H2 + O2 -> fire
|
| Like methanol -> die, ethanol -> fun, propanol -> die,
| butanol -> die, heptanol -> die, octanol -> die
| ashtonkem wrote:
| And that's why I said "most".
| masklinn wrote:
| > Uh, except the stuff you shove on your toothbrush?
|
| Fluoride is an exception, only in small quantities, and
| only topically (lots of salts are toxic, and so are
| concentrated solutions).
|
| By and large fluorine chemistry is a giant pile of nope, so
| staying away from it is an excellent rule and quite far
| from a "super, super, non-convex".
| rakejake wrote:
| My high-school chemistry teacher had this joke: "If you
| drink Ethanol you dance around people, if you drink
| Methanol, people end up dancing around you". For context,
| certain communities in India have people dancing around the
| funeral procession.
| FreeFull wrote:
| 1-Propanol acts like ethanol, but stronger, so you'll be
| fine if you don't ingest too much. 2-Propanol on the other
| hand (isopropyl alcohol) gets metabolised into acetone,
| which isn't great. And the only difference between the two
| is the way the atoms are arranged!
| addaon wrote:
| Yes. I've often heard (although it appears to be an open
| question[1]) that chemists have a significantly shorter life
| span than the general population.
|
| [1] https://pubs.acs.org/doi/10.1021/cen-v049n010.p005
| Natsu wrote:
| Yeah, most of the time I've read about such compounds it was
| via blogs, like this one on dimethylcadmium:
|
| https://www.science.org/content/blog-post/things-i-won-t-wor...
|
| "I'm saddened to report that the chemical literature contains
| descriptions of dimethylcadmium's smell."
| chrisbrandow wrote:
| I still remember this event when it happened. I was getting my
| PhD at the time. I think about it regularly.
| DrAwdeOccarim wrote:
| I started my chem grad school about a decade later and all the
| changes were well accepted and the field was still mourning her
| loss. What a tragedy.
| throwawayboise wrote:
| I wonder if the outcome would have been differnt if she had
| just immediately changed her gloves (or maybe she did? The
| story doesn't really say, but implies that she just continued
| the experiment).
| [deleted]
| verisimi wrote:
| kwohlfahrt wrote:
| Ethylmercury is used insted of (di-)methylmercury, because it
| is cleared from the body faster:
| https://www.cdc.gov/vaccinesafety/concerns/thimerosal/index....
| bogota wrote:
| No its not as you pointed out but didn't clarify. Ethylmercury
| is not the same as methylmercury.
| hammock wrote:
| It is not. The mercury in (some, but not all or even most,
| these days) vaccines is ethyl mercury. Here is an article that
| explains a bit more of the similarity with dimethyl mercury,
| though - they are both organic mercurials:
|
| >Both ethyl mercury and Hg2+ are very neuro toxic compounds.
| However, ethyl mercury is more rapidly partitioned into the
| hydrophobic (fatty) tissues of the central nervous system and
| is a more potent neuro toxin than Hg2+ based on this
| "partitioning factor". It is this partitioning factor that
| makes organic mercurials such as dimethyl mercury so neuro
| toxically lethal (this is the compound that caused the death of
| a Dartmouth University chemistry professor after she was
| exposed to a drop or two on her gloved hand).
|
| >The concern with organic mercurials, such as thimerosal, is
| that such compounds can be perceived as "pro toxicants" just as
| certain pharmaceuticals can be classified as "pro drugs". This
| means that the original compound, e.g. thimerosal, is less
| reactive giving the compound time to partition into certain
| areas of the body before it breaks down releasing the ethyl
| mercury and then further releasing Hg2+. However, while
| attaching ethyl mercury to thiolsalicylate makes the ethyl
| mercury less reactive it most likely allows increased
| partitioning into the central nervous system before the ethyl
| mercury is released and thereby, increases the neuro toxicity
| per unit ethyl mercury involved
|
| https://vaccinechoicecanada.com/vaccine-ingredients/thimeros...
| bawolff wrote:
| I would think it would go without saying vaccines don't use one
| of the most toxic substances known by virtue of the fact people
| aren't dropping dead.
| mahkeiro wrote:
| When I was studying chemistry, latex gloves were not allowed in
| org chemistry lab as too many thing can go through them and they
| provide a false sense of security.
| throwawayboise wrote:
| I didn't take chemistry past freshman general chem, but we
| didn't use gloves at all. Eye protection, yes.
| julienchastang wrote:
| Note the time between initial exposure and death -- almost a
| year. Terrifying.
| brazzy wrote:
| And about 5 month before any symptoms showed up, then comatose
| within 3 weeks.
|
| I once asked a biochemist how that's even possible. Apparently
| it irretrievably destroys a part of the body's metabolism that
| is necessary to repair nerve cells.
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