Hermes_Trismegistus
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Registered: 27-11-2003
Location: Greece, Ancient
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Chemical Storage and Temperature
Currently I store my chem's in plastic bags, in glass mason jars, in plastic jugs, and in metal tins (original solvent jugs) and place all of the
above in plastic bags.
However, they are not isolated from each other enough.
Acids/Bases/solvents/oxidisers/etc.
I was thinking of constructing storage cabinets out on my balcony (which is secure).
I wonder if there is any contra-indications for low cold storage for anything?
It can go to -35 degrees celcius in the shade here for extended periods.
Arguing on the internet is like running in the special olympics; even if you win: you\'re still retarded.
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The_Davster
A pnictogen
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I don't think that cold temps would be too bad for most chemicals(unless you plan on storing some nitroglycerin...). I would be more worried
about the maximum temperature as the decomposition of some chems, example nitric acid, is accelerated at higher temps.
It all depends on what you are intending to store. Would it be possible to post a list of what you plan to store out there?
[Edited on 31-8-2004 by rogue chemist]
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chemoleo
Biochemicus Energeticus
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Liquids (solvents, acids, bases, solutions): Definitely not outside. You dont want your bottles to burst once the contents freeze.
Conversely organics often don't like heat, equally light/UV. Same for other photosensitive compounds.
Oxidisers also away from heat.
I guess what it would be best for is bulk chems, which take up space and are cheap and simple in nature. Such as salts etc.
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
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Hermes_Trismegistus
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I was more concerned about stability than the type of containers bursting, but you are right, in that anything water based or containing watergoes
through a period of expansion when it freezes before it starts shrinking again.
That's something to be concerned about, but I guess that non-polar's like acetone, xylene and whatnot should be fine.
I was already under the impression that stability generally increases with temperature decrease, but I have never actually heard that stated as a
rule, so why not check eh?
Arguing on the internet is like running in the special olympics; even if you win: you\'re still retarded.
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David Marx
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You are quite right, with very few exceptions, chemicals are more stable at lower temperatures. This is because at lower temperatures, there is less
ambient energy to fuel rotations, vibrations and exchange actions.
If you are sure your containers are up to it, there is no good reason why you can not store the majority of your chemicals at reduced temperature. Be
careful to avoid UV exposure though or any benefit you get from lower temps could be conteracted by photodegredation.
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mick
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Chemical storage and temp
The most common thing on a label is to store in a cool dry place out of sunlight and at as near to a constant temp as possible. If they are kept cold
they also need to be kept dry otherwise that seems to be worse than being and slightly warm and dry. A good freezer bag sealer seems to work.
Polyethylene and polypropylene tops seem to be better than the hard plastic tops, conc nitric and fuming sulphuric acid takes a few years to to go
through them.
If you do not expect a fire most thing can be stored next to each other if the are well sealed, check under any kitchen sink. If there could be a fire
and you have got oxidising and organics next to each other then make sure everyone goes away from them.
The stuff I have been trying out to seal chemicals is the stretchy polyethylene insulation tape that is apparently used in Alaska and I also have been
told is use on boats . Its not sticky but it is chemically resistant, takes out air and water when you wrap it round, high insulation, self
amalgamating and it is supposed to work from -95 oC to I think above 50 oC or more (I will have to check, I think it is higher than that).
If anyone is into cryogenics
Since I have wrapped a bit of plastic tubing with it that carries a some liquid N2 once a week you do not have that nice sound of the plastic just
shattering sometimes. Is it better or is it more boring.
Mick
How did the perchloric acid get out the bottle
Someone had a bottle of 70% perchloric acid on a shelf over a wooden bench. I noticed liquid dripping down the side of the bottle and a ring of liquid
round the bottle. Seriously acid, I am sure it was perchloric acid.
The only thing I could think of was the bottle had a plastic pouring ring on and the top did not have the original seal. I though it was acting as
something like a heat pump with a one way valve, cold at night and hot during the day, pumping out perchoric acid vapours and picking up water on the
way.
But I have since read that 70% perchloric acid has negligible vapour pressure at these temp
mick]
[Edited on 1-9-2004 by mick]
[Edited on 1-9-2004 by mick]
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