Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Organic Chemistry Forum for Graduate Students and Professionals => Topic started by: nj_bartel on October 15, 2008, 08:28:56 PM
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I'm supposed to be running my first synthesis tomorrow, and I just realized I don't have the slightest idea of the toxicity of the product, not to mention potential byproducts. It should only have to have NMR run on it. How do you all treat these substances?
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As long as you don't eat it and it isn't volatile you don't have to worry. Most toxicity concerns are mitigated by the unknown molecule having a low vapor pressure and doesn't dissolve through your gloves.
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Ok, thanks. It should have very low volatility, and there isn't anything really hazardous it could release if it's unstable and decomposes.
Thanks.
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Ok, thanks. It should have very low volatility, and there isn't anything really hazardous it could release if it's unstable and decomposes.
Thanks.
Most common dangerous compounds in org chem lab: azides, cyanide (+acid), HF, and phosgene (at least in our lab)
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My own rule of thumb is, if its unknown toxicity wise, treat it as though it were at the least as toxic by weight, and as fast acting as hydrogen cyanide, also, handle as though the compound is quite volatile and flammable.
It probably isn't, but do you want to find out the hard way?
Just look at what could have happened to the people looking at organophosphate insecticides, who discovered the nerve agent tabun, a drop (yes one drop!) was spilled outside the fume cupboard in the lab it was synthesized in, and within seconds the technicians vision blurred, caused severe lachrymation, salivation, sweating, some muscle fasiculations etc, all typical anticholinesterase nastiness.
They were lucky, they got out in time, but they were quite ill for a fair while, and excepting very simply structured fluorinated OPs like diisopropylfluorophosphate, tabun is the least toxic of any of the military nerve agents, just think what would have happened if it had been one of the novichok series, or V agents, those techs would have died where they stood most likely (and quite certainly were they exposed to novichok type agents, as they already contain an oxime functional group, and cannot be deactivated by oxime-based nerve agent antidoes, and thus remain bound to acetylcholinesterase) those chemists would have been well and truly buggered, but had they been using nonpermeable double-layered glovebox, full NBC gear and negative pressure lab, oxygen supplies, they would have survived (although the tabun incident, none of the techs died)
Granted full-on NBC kit is overkill in most any chemistry lab (although what wouldn't I give for a moon-suit, would prefer that over a gas mask, goggles and leather anyday, although I reckon it might s#*$ the neighbours up a wee bit ;D)
The theme is, if you don't know, assume its lethal at low levels, and take precautions, whatever your doing probably isn't quite that dangerous, but on the off chance it is, and you have prepared for it, a leak or spill is bad news, but its better than your other half waving you off in a box.
Bette to have the security, and not need it, than need it, and not have it.
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This is an old thread but it's worth saying:
No one mentioned the most important thing: never work alone on a new synthesis. Really, one should avoid working alone in the laboratory as much as possible! Second most important thing is to use commonsense.
I would look and see what similar compounds/cognates are like with respect to toxicity and other properties (mutagenics, carcinogenics etc.).
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Working in full NBC protective equipment is probably an over kill. But if you don't know anything about the toxicity be carefull.
*Make sure your fume cupboard works well, use a piece of paper to check the flow. Do all your work inside there, also your NMR sample.
*Use appropriate gloves. You can use a double set, and change them often. Butylrubber gloves are impermeable, but not that good to work with.
*and as "Fleaker" said, never work alone
-m