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Is Melted Bismuth safe to wear as a necklace?

  1. Oct 17, 2018 #1
    Is melted bismuth safe to wear pretty much 24/7 around your neck ? I don't want to get a super low radiation hyper bug cancer fungus to appear after 30 yrs....
    (It touches your skin permanently unless you're running ofc)

    On top of that, can I smelt bare bismuth (99%) in my kitchen or should I wear a gas mask to prevent my nose from sniffing up all the fumes:biggrin:?
     
  2. jcsd
  3. Oct 17, 2018 #2

    DrDu

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    Bismuth melts at 271 degrees C, so molten Bismuth will burn a nice hole into your neck!
    While this is falling out of fashion, Bismuth compounds are even used orally against heart burn, so wearing a necklace made of Bismuth will be harmless.
    As far as radiation is concerned, Bismuth was considered non-radioactive until not too long ago when it was found that it decays with an extremely long half life time. Far to low to be of any concern.
     
  4. Oct 17, 2018 #3
    I think its pretty clear with the first sentence how expierenced I am in terms of terminology ;).
     
  5. Oct 17, 2018 #4

    jim mcnamara

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    Bismuth is okay to work with. Cold. Or wear. It is safer than metals like lead or antimony. It is not perfect for human jewelry nor is it close to inert like gold:
    https://en.wikipedia.org/wiki/Bismuth#Toxicology_and_ecotoxicology

    Melting and casting a lost wax pendant should be an outdoor activity if you have never done it. For safety reasons you might want to take a silversmithing class at a local VocEd college. You could melt Bismuth in a hot oven or on the stove top, but you need a crucible and tongs to play safely with a hot liquid. Teflon lined cookware will not work. A spill of dense liquid at 271 °C is not going to endear you to whoever owns the kitchen. Your foot won't like hot metal either.

    But why bismuth? Silver is more cost effective and generally more safe to wear. Take a class. Then you get free access to everything you need, except silver or maybe something cheaper to practice on like copper. Bimsuth lists $98.00USD for ONE ounce (25g) at Aldrich. Silver from Thunderbird jewelery Supply is less than $10.00USD per troy ounce last time I looked.
     
  6. Oct 17, 2018 #5

    DrDu

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    I've molten bismuth in my wild youth myself. You won't need a gas mask, but safety googles are a must!
     
  7. Oct 17, 2018 #6
    Silver also melts at 960 Celsius.

    Aldrich seems to be remarkably expensive supplier for small quantities of chemically pure stuff. This:
    https://www.metalbulletin.com/Artic...ice-hits-2018-low-on-oversupplied-market.html
    quotes bismuth as US$ 4,40 or less per pound.

    Low melting moderately reactive metals are:
    nontoxic:
    Bi - 271 Celsius
    Sn - 232 Celsius
    In - 156 Celsius
    Zn - 410 Celsius
    toxic:
    Pb - 327 Celsius
    Tl - 304 Celsius
    Cd - 321 Celsius

    If the goal is casting with easy tools and low temperature, then the obvious nontoxic alternative would be pure tin (without lead alloy component). Or zinc, but zinc is higher melting. Indium has special applications, but is remarkably expensive.
     
  8. Oct 17, 2018 #7
    May I suggest that, as a precaution, you seal your cold, trimmed & smoothed casting with multiple coats of lacquer before putting it against your skin ??
     
  9. Oct 19, 2018 #8

    DrDu

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    I like the idea of bismuth. Bismuth makes some nice crystals with shiny interference colours.
     
  10. Oct 23, 2018 #9
    There's something about this thread that I find disturbing... :rolleyes:
     
  11. Oct 23, 2018 #10

    DaveC426913

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  12. Oct 24, 2018 #11
    Hmm.. I don't agree. I say no to Tin!
    Pretty much all non noble metals not protected by a surface oxide are very toxic! Especially stannous anything! Even the whole thing about replacing lead with tin in PCB solders seems to be a misplaced effort!

    The copper content in brass swing door handles often used in older hospitals ensured the death of microbes and many virus in seconds or minutes. Maybe that was just fortuitous, but now, you use a poisonous hand gel instead, and the door furniture is plastic!

    Aluminum is so reactive that it forms a transparent self-limiting thickness of oxide in seconds from a clean cut. It is safe to put against the skin. Some say that aluminum adsorption might have links to Alzheimer's symptoms, but I honestly don't know if that is proven, or even plausibly suggested.

    Right up to iron, even those oxides, some actually normal, or essential, in human physiology, are toxic when in excess.

    I would not even give two cheers for silver if in compound form, and I would not think that black silver tarnish compounds are likely to be benign. Gold, Platinum are maybe not called "noble" for nothing. You are safe with them!

    Bismuth has unusually low toxicity among heavy metals, because of the low solubility of bismuth salts, and can be expelled from the body in a few days unless one is being treated with bismuth compounds as medicines, but the substance itself is toxic if it makes it into you as a compound.

    Either way - Tin is poisonous! Zinc is poisonous!
    https://en.wikipedia.org/wiki/Tin_poisoning
    https://en.wikipedia.org/wiki/Zinc_toxicity
     
  13. Oct 24, 2018 #12

    jim mcnamara

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    @GTrax - probably not. You are exaggerating. Not acceptable. You do know the Bismuth is found in anti-diarrheal medication, right? I am leaving your comments as your wrote them, but they are not helpful in any way.

    Your Zn toxicity article notes that 2000 mg dosage of Zn for several months showed no clinical systems other than a likely reduced Cu absorption rate.

    Please do not play "fake news", cite LD50 data. For example MSDS for Zn metal does not show an LD50 value, because toxicity is very mild and very occasional. Welding galvanized metal (Zn coating) is a problem because welding temperatures vaporize zinc metal coatings. The Zinc gas damages tissues in the lung.
    MSDS:
    http://www.sciencelab.com/msds.php?msdsId=9925476

    ZnO - zinc oxide is used in foods. Zn is a required element in the human diet.
    http://www.sciencelab.com/msds.php?msdsId=9927329
    https://en.wikipedia.org/wiki/Zinc_oxide - Zinc oxide is used as sunblock (sunscreen) - the white stuff you see on lifeguard's faces. It also used as a food additive, usually in products like breakfast cereal.

    You are exaggerating. Please. Read the MSDS before you go further off the deep end.

    Almost anything in huge excess can cause a problem. Zn toxicity is not in a class with Pb toxicity.
     
    Last edited: Oct 24, 2018
  14. Oct 29, 2018 #13

    DaveC426913

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    Indeed. As they say: The dose makes the poison.

    There's a cool chart out there somewhere that shows how much of a given substance makes it toxic. Even water is on there.Wish I could find it.
     
  15. Oct 29, 2018 #14

    jim mcnamara

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  16. Oct 29, 2018 #15

    DaveC426913

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    Oh, I looked around. Haven't found the chart I was thinking of though.
    It had a vertical axis, with water at the top, with the widest bar, and various toxins at the bottom and about a hundred things in between.
     
  17. Oct 29, 2018 #16

    ras

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    The problem with bismuth as jewelry is not its toxicity (as noted already is very low) but rather practical. It shatters pretty easily. And if you're wearing a bismuth crystal, which is the most likely form to be worn as jewelry, the colorful oxide coat will rub off pretty soon.

    And don't worry about that ridiculous Aldrich price quote. You can find bismuth cheaply on ebay, Amazon and Luciteria (which carries all possible elements)
     
  18. Nov 30, 2018 #17

    CWatters

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    Re earlier comments about zinc...I think zinc oxide is used in creams to prevent nappy rash in babies.
     
  19. Dec 1, 2018 #18
    ...and about tin: it's used (and of course allowed by the laws) in some copper containers for food, as internal layer.

    --
    lightarrow
     
  20. Dec 7, 2018 at 6:33 AM #19
    Yes, molten bismuth will definitely burn. Something I found out recently is bismuth salts might have a much longer half life than traditionally believed. I have read alot of convincing website articles about new research suggesting that bismuth salts can be detected weeks if not months after administration, so bismuth may not be as harmless as people think
     
  21. Dec 7, 2018 at 6:47 AM #20

    Klystron

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    In a chemistry set intended for children circa 1960's, bismuth, probably a sulfate (?) or sulfite, was provided in a tiny glass jar labeled "dangerous" but not poisonous. I saw a similar substance in great abundance marked with a purple trefoil at Poulter chemical labs at SRI (Stanford Research Institute not the University) thirty years later.

    Bismuth compounds may appear in certain pigments. [I won't mention the concoctions the laser scientists used in the "Vision Lab"; but don't spill them on the floor.]
     
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