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B(a)P
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I have worked with inorganic mercury both in the occupational and home chemistry environment. I have worked with organic mercury but only at ppm
concentrations, I have never worked with pure organic mercury compounds, it would be interesting, but extremely costly to have the appropriate
controls in place. It is highly unlikely I will ever have the opportunity as the application of organic mercury compounds are extremely specialised.
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Fyndium
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I would love to see a bottle of dimethylmercury only because of it's renowned toxicity and how abstract and at the same time boring that one-liter
bottle would look like. I still wonder how it was handled in wherever it was produced and used for any reason whatsoever? It probably needs similar
containment than nuclear material handling facilities, with remote handling.
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Xanax
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Once I experimented with HgCl2 (I was only 14 years old then), heated it up in a test tube, and it all sublimated and I got all the gas in my face!
Maybe it partly caused some of my psychiatric problems I'm suffering from, today? I know I got a lot of lead in me too, from lead-compunds and lead
from batteries.
[Edited on 2021-5-16 by Xanax]
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Fantasma4500
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i would never handle mercury salts. having been poisoned with nickel (oxalate, quite insoluble) by just carefully evaporating down a solution of it
during an attempted chromium/nickel/iron seperation of stainless steel, just stirring the pot of nickel-iron-chrome oxalate every now and then got me
a 2 day nickel poisoning, very annoying tremors
and ive been exposed to plenty nickel through metal work, never had any kind of effect like this before, and this was just from the fumes of the water
solution of the rather insoluble nickel oxalate
i dont consider it brave to handle mercury salts, i consider it stupid. its nightmarishly toxic. knowing that even solid water, ice will sublimate
over time would explain you that even a stillstanding solution of mercury salts, or any kind of tending mercury salts will expose you to some amount
of mercury, i will advice to supplement with selenium if you ever dare to handle mercury.
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Fyndium
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Evaporating anything will cause the stuff to aerosolize and you effectively poison yourself. When I concentrated some metal salts, I did that in
distillation apparatus or outdoors in such way that I could operate the heater from over 5m away, upwind, and I held my breath when I went closer to
observe the contents.
I don't consider inorganic mercury too toxic when proper precautions are taken. Biggest risk is likely when handling larger amounts and have reaction
vessel tip over or crack, and even then the major suffer will be contamination of your workspace, unless properly contained.
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theAngryLittleBunny
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What makes me so uncomfortable with heavy metal salts like these of mercury is that any exposure harms you. Sure, with around 300 to 500mg of
inorganic mercury being around the lethal dose it's really not potent, but just getting 30mg of it in your body already chronically damages you.
I'm not scared of potent compounds, I've handled pure benzodiazepine powders with an active dose in the 200ug range, I would even be even okay with
handling fentanyl (never have though lol), no problem, because as long as I don't get exposed to too much of it at once I'm fine, but it's not like
that with heavy metals.
[Edited on 12-9-2021 by theAngryLittleBunny]
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Tsjerk
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Quote: Originally posted by theAngryLittleBunny  | What makes me so uncomfortable with heavy metal salts like these of mercury is that any exposure harms you. Sure, with around 300 to 500mg of
inorganic mercury being around the lethal dose it's really not potent, but just getting 30mg of it in your body already chronically damages you.
I'm not scared of potent compounds, I've handled pure benzodiazepine powders with an active dose in the 200ug range, I would even be even okay with
handling fentanyl (never have though lol), no problem, because as long as I don't get exposed to too much of it at once I'm fine, but it's not like
that with heavy metals.
[Edited on 12-9-2021 by theAngryLittleBunny] |
This sounds very strange to me, how can any exposure harm? There are amounts that don't harm at all, and they are definitely above the amount of a
fentanyl exposure that would.
I think what you are referring to is the cumulative nature of these heavy metals, maybe a milligram won't hurt, but a milligram every year would hurt.
Whereas a sublethal dose of a benzo every now then will never amount to a dose that would be lethal.
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woelen
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It's indeed the cumulative effect of mercury, which is scary. Mercuriy(II) has a body half life of well over 10 years. So, a dose of 10 mg taken now
means that after 10 years you at least have 5 mg of that left in your body. If you get 10 mg once a year, then after 10 years you will have somewhere
between 70 and 80 mg in your body.
Compare this to the half life of cyanide. This is lethal in 250 mg doses. But the body half life of cyanide is expressed in hours, so after a day,
most of the cyanide has been metabolized into something else and after a few days, no detectable levels are present anymore. So, if you get sublethal
doses, then after a few days, when you again get a sublethal dose, the body again can withstand the full dose.
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j_sum1
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Thanks for the reminder, woelen. I had temporarily forgotten about bioaccumulation.
Which speaks to the folly of considering just one parameter when considering safety matters.
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Oxy
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| Quote: Originally posted by woelen |
Compare this to the half life of cyanide. This is lethal in 250 mg doses. But the body half life of cyanide is expressed in hours, so after a day,
most of the cyanide has been metabolized into something else and after a few days, no detectable levels are present anymore. So, if you get sublethal
doses, then after a few days, when you again get a sublethal dose, the body again can withstand the full dose. |
I agree with elimination half-life.
But it may be not so easy to withstand the same dose few days later. If the amount was not lethal and didn't kill that doesn't mean it was harmless.
The damage made by hypoxia might be severe (but just no lethal), another one "full dose" might be too much
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S.C. Wack
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| Quote: Originally posted by Antiswat | | i would never handle mercury salts. having been poisoned with nickel (oxalate, quite insoluble) by just carefully evaporating down a solution of it
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These are dubious statements for which I doubt any experimental proof can be shown (no surprise that they're in a mercury thread). Boiling can produce
aerosols, sure, OK...even dissolving NaOH in water famously produces fumes by an unclear mechanism (steam from not-boiling, dissolved NaOH solutions
is totally non-irritating)...but I'd like to see some sort of evidence for such claims. Certainly references can be found for human and animal
excretion of inorganic, organic, and elemental mercury, but do any show a half-life of more than 90 days? Dental amalgam hysteria would be
even more profound if it could be proven that the miniscule amounts released were accumulated.
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B(a)P
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| Quote: Originally posted by woelen | It's indeed the cumulative effect of mercury, which is scary. Mercuriy(II) has a body half life of well over 10 years. So, a dose of 10 mg taken now
means that after 10 years you at least have 5 mg of that left in your body. If you get 10 mg once a year, then after 10 years you will have somewhere
between 70 and 80 mg in your body.
Compare this to the half life of cyanide. This is lethal in 250 mg doses. But the body half life of cyanide is expressed in hours, so after a day,
most of the cyanide has been metabolized into something else and after a few days, no detectable levels are present anymore. So, if you get sublethal
doses, then after a few days, when you again get a sublethal dose, the body again can withstand the full dose. |
I think the half life for inorganic mercury is much less than you state, more like months than years.
"Biomonitoring Summary | CDC" https://www.cdc.gov/biomonitoring/Mercury_BiomonitoringSumma...
"Evaluation of mercury exposure level, clinical diagnosis and treatment for mercury intoxication"
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4724159/#:~:text=The%20mercury%20absorbed%20in%20the,(2%E2%80%9310%20%25).
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woelen
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| Quote: | | [...]But it may be not so easy to withstand the same dose few days later. If the amount was not lethal and didn't kill that doesn't mean it was
harmless. The damage made by hypoxia might be severe (but just no lethal), another one "full dose" might be too much |
Fair point. As long as there still is no full recovery, then the body may still be weak. But once you have fully recovered, the same dose can be
handled again.
| Quote: | | I think the half life for inorganic mercury is much less than you state, more like months than years. |
I even read numbers of 27 years or so, especially once the mercury made it into brain tissue. For me, these numbers are quite scary, and for this
reason I prefer working with cyanides or azides (a few mg of exposure of these hardly does any harm) and if in another experiment, let's say a year
later I again get a similar exposure, then there is no issue. So, infrequent experimenting with cyanide or azide introduces risks, which can be
assessed independently, regardless of history. Infrequent experimenting with mercury leads to increased risk, each time you do a new experiment, even
if the experiments are one year apart in time.
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Texium
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woelen, with all due respect, your claims are completely outlandish and directly contradict the source that B(a)P posted. Please provide a source if
you are going to stand by this claim of a decades long half life.
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Fyndium
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I have read both of those statements. In various sources, it is stated that inorganic mercury will have half-lifes in like 30-60 days or so, meanwhile
some sources state that mercury has a half-life of decades, basically what you ingest, you will carry to your grave, either prematurely or not.
Personally, I err on the safe side with any heavy metals or stuff that has a bioaccumulation potential of such degree.
About fentanyl, the first mistake you do with it will be your last mistake. It's not just carfentanil, but the ordinary one that will knock you out
standing. Your only solace is it will be quite painless an comfortable to you. That's why I would not dare to handle it, unless I have full body PPE
with P3 face mask respirator, and in any event at least one person accompanying with multiple doses of narcan, because once you realize you got
exposed and OD'd, it is highly unlikely you will be able to self-administer before you lose your consciousness. Many other substances, even having a
very low OD threshold, will not act as a contact anesthetic(it doesn't actually poison you transdermally not easily at all unless handling raw
material with moist hands, but any amount of dust will make you breath it in, and that's it) but give you time to administer antidote or call for
help. Also, I would not touch it with a ten feet pole outside any institution because it carries the most severe penalties that are ridiculously hefty
in where I live.
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woelen
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| Quote: Originally posted by Texium | | woelen, with all due respect, your claims are completely outlandish and directly contradict the source that B(a)P posted. Please provide a source if
you are going to stand by this claim of a decades long half life. |
See here: https://en.wikipedia.org/wiki/Mercury_poisoning
The statement is in the section on prognosis.
It mentions a half life of inorganic mercury in brain tissue of 27.4 years. My number of 27 years does not come from this though, I once read a
similar thing in another online article. I'll try to find that as well. Source number [56] is the origin of this info.
In other human tissue the half-life is lower, but I have seen values of around 10 years, which also is quite scary to me.
For this reason I never did experiments with stuff like mercury fulminate. It is interesting stuff and although I am no real energetic materials
person, experimenting with such things on 100's of mg scale can be quite entertaining, but if I read a thread like this (http://www.sciencemadness.org/talk/viewthread.php?tid=24028 ), then I really feel horrified. People discuss risks (violent reaction, fire,
explosion), even toxicity of the NO2 and other gaseous products, but no one mentions the risk of exposure to Hg! If I would have such a reaction
inside, with a big brown plume of NO2 escaping from the beaker, I would be shit scared, not because of the NO2, but because of the mercury salts,
which are taken with it as fine droplets. I simply leave the room and after an hour all NO2 is gone, but what with the mercury? All tiny droplets have
evaporated to dryness and little particles of dust have settled on the floor, on the furniture, etc. Every day I get into that room I may get exposed
to a few micrograms of mercury, which I will carry with me for at least years to come and maybe decades to come.
I do not even want to think of actually doing small explosions with the mercury fulminate . . .
[Edited on 15-9-21 by woelen]
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Texium
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Alright, I see. That is very scary. However, it is still misleading in the context that was presented with it earlier in the thread. Mercury that is
able to reach your brain tissue may effectively be with you for life, but it’s important to acknowledge that most mercury (especially inorganic
mercury) does not actually reach the brain. So your math here:
| Quote: Originally posted by woelen | | It's indeed the cumulative effect of mercury, which is scary. Mercuriy(II) has a body half life of well over 10 years. So, a dose of 10 mg taken now
means that after 10 years you at least have 5 mg of that left in your body. If you get 10 mg once a year, then after 10 years you will have somewhere
between 70 and 80 mg in your body. |
is rather misleading, given that most of that mercury will be excreted within weeks, based on all the data that has been shared.
[Edited on 9-15-2021 by Texium]
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woelen
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I agree with you. Not all mercury you get in your body will make it into the brain tissue. Part of it will be excreted.
So, things are less scary than I stated, but still quite scary. Which part does make it into brain tissue?
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andy1988
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Mercury pharmacokinetics is a search phrase I'd use, I don't know of any better terms to use to find papers to evaluate. I'm not really
interested in mercury.
I guess an interesting tangent would be gadolinium, used in chelated forms as a contrast agent in MRIs.
I'm sure you may have heard of Chuck Norris and seen jokes/memes regarding his character in films. No one is immortal! Says he retired from acting in
order to care for his sick wife [1][2]. Later all parties withdrew from the suit paying their own legal fees. Personally I'd reason that putting the burden of proof on
non-specialist consumers ("market evaluation") rather than paying researchers for decades to figure things out is foolish, other arguments too.
Edit: PBS article on the U.S. FDA increasingly approving drugs without conclusive proof they work.
From my understanding more chemically stable chelated forms are available now which are claimed to have 100% excretion, other articles detail this.
[Edited on 15-9-2021 by andy1988]
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unionised
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A lot of work has been done on the toxico-kinetics of mercury (with and without organo bits).
https://www.epa.gov/sites/default/files/2015-09/documents/vo...
Fir what it's worth, chronic cyanide poisoning is also a problem, but the mechanism is different.
The body "detoxifies" cyanide by conversion to thiocyanate.
But that's toxic to the thyroid as it gets "mistaken" for iodide.
[Edited on 15-9-21 by unionised]
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S.C. Wack
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Organic and elemental (lung-absorbed) Hg would be much more likely to cross the blood brain barrier. Even so, radiotracing has shown that it goes
away.
BTW wannabe poisoners, mercuric salts are said to taste bad, and are more likely to be found out than other poisons.
[Edited on 15-9-2021 by S.C. Wack]
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B(a)P
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| Quote: Originally posted by woelen | I agree with you. Not all mercury you get in your body will make it into the brain tissue. Part of it will be excreted.
So, things are less scary than I stated, but still quite scary. Which part does make it into brain tissue? |
Thanks for sharing your references Woelen. I find this particularly interesting because the assessment of risk to the human or ecological receptor
from environmental contaminants is a big part of what I do for a job. The models used (in Australia) to assess the risk to human health assume
excretion half lives of months not years for mercury. My area of expertise in regard to mercury relates more to fate and transport in the environment,
so I can't comment on the uptake by humans. Interesting fact though after the earlier comment on dental amalgam, the average quantity of interested
seafood drives the background mercury intake loads to the average human body, far exceeding that of amalgam.
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yobbo II
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You can get an idea of mercury vapour rising from metal from this link.
https://www.youtube.com/watch?v=lpZF88fqrl8
Yob
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macckone
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I did some research on mercury a while back, literature not chemical.
For most people there is a chronic exposure level that can be excreted.
So the half-life isn't as relevant as one might imagine.
There is a maximum that can be excreted and in the brain it gets sequestered in a relatively non-toxic form.
So even though the brain half-life is long, that is because the mercury is sequestered.
The primary problem is that both accurate and chronic exposure can damage brain cells which do not rapidly regenerate.
for chronic exposure from fish (methyl mercury) the formula is 0.1ug/kg/day.
But the maximum on kg is about 75kg (regardless of how much you weight).
other forms of mercury are much less dangerous and you can find information on bioavailability.
So an upper limit for an adult is 7.5 ug/day for chronic exposure.
One time acute is going to be less than 1mg of methyl mercury.
The vapor concentration is 2mg/m3 for methyl mercury idhl.
for other mercury compounds it is going to be more.
https://www.epa.gov/fish-tech/epa-fda-fish-advice-technical-...
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teodor
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But now I see why "I'll eat my hat" was a very serious argument.
I doubt I can write something useful for experienced chemists, but for people who are starting chemistry trying different inorganic reactions, I
suggest doing experiments with nitrobenzene before any experiments with mercury.
Nitrobenzene is also a nice compound and could be used for many interesting things but also a very toxic one with the same possible routes of
poisoning as for mercury salts - breath, skin, penetrating through gloves (it easily dissolves nitrile). Also sometimes people say it has a cumulative
effect and can do irreversible damage.
The only difference is that you always know when you got some dose (most likely you will have a headache the same day) and you can always detect even
a tiny amount by smell, so you will know when something around you is contaminated. But it is very educational because it is enough a small not
visible droplet to land on your skin (like when you wash your glassware) to get some kind of poisoning symptoms.
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