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I was working in the lab preparing Tollens’ reagent. When I came back home, I observed that my fingertips were brown, and I tried to wash it with soap several times but it didn't work.

It has been a day and they don't seem to go.

What may have been the reason? Is it permanent and how can I get rid of it?

orthocresol
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Prakhar
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    Let that be a massive wake-up call. The three things that matter most in a chem lab? SAFETY, SAFETY, and SAFETY. Have a safety plan and know how you are going to properly dispose of all waste before you start any experiment. We don't about safety nearly enough on this site. – MaxW Sep 22 '16 at 13:27
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    The stain will wear off your fingers in a few days. Just wait... – MaxW Sep 22 '16 at 14:06
  • Here's the canonical cautionary tale: https://en.m.wikipedia.org/wiki/Karen_Wetterhahn – Jim Garrison Sep 22 '16 at 17:00
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    @JimGarrison - I'd take some exception to your example. It is entirely possible to get exposed in some way or by some chemical where the problem is yet unknown. That is a small risk associated with being a chemist. What is STUPID is to ignore the science that we do know. Cyanide is toxic. Rubbing it on your fingers and dying isn't an accident, as in the case of Dr. Wetterhahn, it is plainly just STUPIDITY. 99+% of "accidents" in a chemistry lab could be avoided with a proper consideration for known safety factors. – MaxW Sep 22 '16 at 18:28
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    Of all things that can leave long-lasting marks on your skin, silver is probably the least harmful. In a way, it might even do you a little good because of antimicrobial activity. Your attempts to get rid of it, though, might be REALLY dangerous. Just leave it alone, or you'll end up in a textbook, and not quite in the role of Tollens or Fehling, but rather like Karen Wetterhahn or Sheharbano Sangji. – Ivan Neretin Sep 22 '16 at 19:24
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    @MaxW I made a small edit to your comment because I removed the comment you were replying to. – jonsca Sep 22 '16 at 22:40
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    @jonsca - Don't understand what is going on, but ok. The OP read somewhere on the web that cyanide could be rubbed on fingers to remove the silver stains and inquired about that. That is absolutely not safe. Using cyanide like that is of course is so moronically stupid as to be in Darwin Award territory. https://en.wikipedia.org/wiki/Darwin_Awards // I also tried to make the point that the biggest safety problem is making a small mistake then doing something really stupid to try to fix the mistake. – MaxW Sep 22 '16 at 22:55
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    Turing a small mistake into a stupid - Had a classmate set a beaker of organic solvent on fire. He used a Bunsen burner to heat a flammable solvent. Very bad planning. Then the numb-numb carried the burning beaker past other students through the lab with tongs to the stone sink. Mistake X 10 . Still unhappy the numb-numb knocked the beaker over in the sink to get the solvent to burn more quickly. Now we are at first mistake X 100. The solvent of course flashed. Thankfully no one was hurt. He should have just put an asbestos mat or cover glass on the beaker in-place and put out the fire. – MaxW Sep 22 '16 at 23:06
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    @MaxW Yeah, I was trying to avoid mentioning the substance in the comments so that someone wouldn't run across this and try it. – jonsca Sep 22 '16 at 23:23
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    Although the four close votes aged away, I still consider “(…) I observed that my fingertips were brown, (…) What may have been the reason? Is it permanent and how can I get rid of it?” to be a personal medical question in accordance with the Help Center: “Personal medical questions are off-topic. We can not safely answer questions for your specific situation and you should always consult a doctor for medical advice.” –  Nov 15 '16 at 15:28
  • I'm voting to close this as a personal medical question. – Melanie Shebel Dec 02 '16 at 21:54

1 Answers1

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The stains are due to silver nitrate, the reactive portion of Tollens’ reagent. It is very prone to reduction to metallic silver.

If you got it on your hands (a clear signal you weren’t wearing gloves when you should have been) it will create small silver particles in your skin — this is why it won’t wash off. Since the particles are small, they don’t exhibit the classical metallic characteristics (looking silvery, reflecting etc).

Don’t worry, they will grow out within a week’s time or so, due to your skin renewing itself.
And wear gloves next time.

orthocresol
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Jan
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