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Author: Subject: Lab Glassware Cleanliness..
Sniffity
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[*] posted on 11-11-2015 at 20:28
Lab Glassware Cleanliness..


Hey,
So, 2 questions:

Question #1:

So I'm thinking of making some soap. Planning on actually using it, mayhaps selling it...

First thing that came to mind: Glassware has to be clean. I was thinking about buying new glassware. But then I figured maybe that's not necesarry.

So, here's the issue: My glassware is... I'd say relatively safe. Here's a list of things I've done:
-Copper sulfate crystallizations (multiple times).
-One sodium chloride crystallization.
-Prepared nitrocellulose once.
-Prepared different salt solutions (once KMnO4, once sodium potassium tartrate, that's basically it??)

Now, I KNOW that copper sulfate is poisonous. I know that the acids aren't good to be putting on your skin either. Other than these, I've NEVER prepared any organics, so no risk of by-products or anything else being present in the glassware. I've also NEVER used any heavy metals, or otherwise poisonous substances. I've had this glassware for slightly over a year, and due to lack of space and time for experiments, I can kind of recall all I've ever done with it.

I've cleaned the glassware, scrupulously, and soaked it in detergent.

My doubut is: Is this safe enough for making usable soap? Or should I just go ahead and buy new glassware anyway just to be safe?

Question #2:

What about making something edible? Say you wanted to extract some capsascinoids from chili peppers and use it in cooking? IF you were to buy NEW glassware for that, and ONLY use it for making edible stuff... It would be kind of safe, right?
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j_sum1
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[*] posted on 11-11-2015 at 20:33


For Q1.
If it looks clean, make soap.

For Q2
I would be more concerned about what is in the reagents I used than what had been in the glassware -- unless I had been playing with lead salts or worse.
So, new, or meticulously clean glassware and food-quality reagents and I see no reason why you shouldn't.
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Upsilon
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[*] posted on 11-11-2015 at 20:59


The dose makes the poison. The trace amounts of residue that may still be on the glassware aren't nearly enough to cause any harm. You need to eat something on the odds of 20g of the stuff to kill you, and that's by ingestion. I doubt that you even have a microgram still in there after a thorough scrubbing.
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Magpie
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[*] posted on 11-11-2015 at 22:34


Clean your glassware with a hot 10% NaOH in alcohol solution with a little water added. It will sparkle. Be extremely careful when handling this cleaning solution.



The single most important condition for a successful synthesis is good mixing - Nicodem
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ave369
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[*] posted on 12-11-2015 at 01:45


Copper sulfate is mildly poisonous. You would not want it anywhere near your mouth, but that's about it, really.



Smells like ammonia....
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Dr.Bob
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[*] posted on 13-11-2015 at 16:58


Copper is a trace mineral needed for life. But too much is bad also.

I would suggest that if glassware was new, then used for the four things listed above, then washing well should be fine for making soap. If you are doing chemistry for fragrances or soap, no big deal if it appears clean after several washings. If you are making food or drinks, then I would typically use new, dedicated glassware. But keep in mind that pharmaceuticals are made in fixed reactors which are cleaned between uses and drugs are made with some very hazardous chemicals, but the vessels are just washed down well and used for the next batch, which often is a different compound, at least in pilot plants and development labs. I would only be worried if you used something particularly toxic, like some heavy metals (osmium, lead, mercury, etc) or some other toxin.
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