Sciencemadness Discussion Board

Store anhydrous Acetic acid?

nannah - 23-7-2014 at 01:17

Hi, i got a package today containing Acetic acid. I ordered it a few weeks back, but the customs took it. They analyzed the content, and confirmed that it indeed was 99,7 % AA, and so i got it at last. :)

But i am a little bit worried becouse the bag it came in was totally wet inside, and the label were all gone, becouse of the corrosion. And it smells like hell. It must be a leak somewhere.

Should i take it out, and wipe off the acid?

And then, how should i store it?

Thanks in advance. :)

Chemosynthesis - 23-7-2014 at 01:22

Fridge/freezer. Thaw prior to use.

nannah - 23-7-2014 at 01:32

Ok, thanks. Do you think i should take it out of the bag and wipe it down? I dont want to contaminate the food.

Freezer or fridge? Which is better?

Ps. Would 99,5 % be considered glacial?

[Edited on 23-7-2014 by nannah]

FireLion3 - 23-7-2014 at 01:33

I would be very careful touching it, and if I were you I would probably seek legal action. I have seen far too many perfectly legitimate packages destroyed by customs. I've had hundreds of dollars of reagents completely ruined multiple times because customs decided they would carelessly destroy a sealed aluminum bag and use duct tape to tape the bag together. Needless to say when I opened the package I quickly needed to get it into containment because the powder was going everywhere and was not safe to inhale. I swear they cut the bag open and let it sit in open air for 3 weeks straight. A lot of reagents cannot take this sort of exposure to air! For 3 weeks it was "lost" according to the shipping company. Customs had it, for a random inspection, needless to say customs has horrible communication with shipping companies.

I am very surprised your package is intact. Pure Acetic Acid has an extremely distinct and unique smell - I do not even know why they would need to take it apart, one open of the package and it is immediately identifiable. You are very lucky it didn't leak onto a mail carrier. You might not be liable but you would be in a ton of legal things to deal with What else could it be anyways? I bet whomever sent you the bottle packaged it very neatly, yet, customs has very little regard for hazardous shipping. I've had them completely destroy the safe packaging on extremely toxic reagents, so much so that you could smell it/inhale it just by being near it. Mind you, many of these reagents were toxic in air-borne dosages! Talk about safety hazard!

I'm skeptical of why your bag is wet. Acetic Acid is very corrosive, and its definitely not something you want on your hands. Just be careful, treat it like any other hazardous acid spill.

Just one of the consequences of importing things.

forgottenpassword - 23-7-2014 at 01:47

Wipe it dry and leave outside until the smell has gone. It is not corrosive to bare hands. Store at room temperature. Tape up the lid if an odour is detected.
Sniffer dogs are trained to smell acetic acid. It's no wonder that it was opened.

[Edited on 23-7-2014 by forgottenpassword]

nannah - 23-7-2014 at 02:05

Quote: Originally posted by FireLion3  
I would be very careful touching it, and if I were you I would probably seek legal action. I have seen far too many perfectly legitimate packages destroyed by customs. I've had hundreds of dollars of reagents completely ruined multiple times because customs decided they would carelessly destroy a sealed aluminum bag and use duct tape to tape the bag together. Needless to say when I opened the package I quickly needed to get it into containment because the powder was going everywhere and was not safe to inhale. I swear they cut the bag open and let it sit in open air for 3 weeks straight. A lot of reagents cannot take this sort of exposure to air! For 3 weeks it was "lost" according to the shipping company. Customs had it, for a random inspection, needless to say customs has horrible communication with shipping companies.

I am very surprised your package is intact. Pure Acetic Acid has an extremely distinct and unique smell - I do not even know why they would need to take it apart, one open of the package and it is immediately identifiable. You are very lucky it didn't leak onto a mail carrier. You might not be liable but you would be in a ton of legal things to deal with What else could it be anyways? I bet whomever sent you the bottle packaged it very neatly, yet, customs has very little regard for hazardous shipping. I've had them completely destroy the safe packaging on extremely toxic reagents, so much so that you could smell it/inhale it just by being near it. Mind you, many of these reagents were toxic in air-borne dosages! Talk about safety hazard!

I'm skeptical of why your bag is wet. Acetic Acid is very corrosive, and its definitely not something you want on your hands. Just be careful, treat it like any other hazardous acid spill.

Just one of the consequences of importing things.


I think they took it to get analyzed becouse the label with the text that said it was AA were exposed so they couldnt read it. But i agree with you that the smell of it were so distict so they should have known. I have never had any AA before, and i knew right away.


Whats that about legal action? What do you mean? Sue them, or hire a lawyer?

When they first took it they said that i would have to come in and talk to them about what my intentions were with it. But they never called me. :/

nannah - 23-7-2014 at 02:07

Quote: Originally posted by forgottenpassword  
Wipe it dry and leave outside until the smell has gone. It is not corrosive to bare hands. Store at room temperature. Tape up the lid if an odour is detected.
Sniffer dogs are trained to smell acetic acid. It's no wonder that it was opened.

[Edited on 23-7-2014 by forgottenpassword]


So your advice would be to not freeze it? Its summer now, so we have up to 30 degrees C here. Is that too hot?

forgottenpassword - 23-7-2014 at 02:12

Of course. It's easier to use if liquid. The boiling point is 119C. 30C is definitely not too hot. I have a litre bottle stored in my shed. No odour comes from it at all. No one stores acetic acid in the freezer in a working lab. Certainly not in the UK.

[Edited on 23-7-2014 by forgottenpassword]

Chemosynthesis - 23-7-2014 at 02:32

I suggest wiping the exterior and storing in the freezer. That is how most glacial is stored in the labs I work in, per manufacturer reccomendations. Due to the evaporation of acetic acid far below the boiling point, it can be annoying to store free in the lab as well a potential fire hazard. It thaws in your hands, so it's not a big deal thaw either. Just keep a small quantity in a secondary container if you feel the need, ideally in a corrosives cabinet which I doubt you havd. It can burn you, and you should use nitrile gloves rather than latex if you are so inclined.
edit: by the way, read the MSDS. Assuming you're not storing with food, as that is bad lab practice. If you don't have a separate mini fridge for chemicals, storage at room temp isn't really that big of a deal as long as you bear in mind it is a flammable acid.

Oh, and don't forget that freezing things usually causes expansion, so don't make an accident in your fridge, please. Probably not a big deal since your container has been opened and is not sealed. You could ziplock bag the bottle anyway.

[Edited on 23-7-2014 by Chemosynthesis]

forgottenpassword - 23-7-2014 at 02:47

MSDS says that it should be stored above its freezing point. http://avogadro.chem.iastate.edu/msds/acglac.htm

Chemosynthesis - 23-7-2014 at 03:02

Quote: Originally posted by forgottenpassword  
MSDS says that it should be stored above its freezing point. http://avogadro.chem.iastate.edu/msds/acglac.htm

Solely due to people stupidly freezing unopened bottles. It is accepted practice to store below freezing point, though flammable rated fridge/freezers are recommended. Note that iGEM held at MIT claims freezing is safer than standard laboratory condition storage. The reason for freezing is to save cabinet space and sequester from oxidizing acids, which are incompatible. Where I am now only devotes a small cabinet to this as we don't use enough glacial to justify the space. Additionally, my locale routinely has exterior temperatures above the flashpoint for acetic acid, and it's considered a safety protocol.
http://www.uofmhealth.org/health-library/d04033a1
http://2011.igem.org/Glacial_Acetic_Acid_Safety_Notes
http://www.drugs.com/mtm/acetic-acid-and-aluminum-acetate-ot...

unionised - 23-7-2014 at 12:43

Quote: Originally posted by forgottenpassword  
MSDS says that it should be stored above its freezing point. http://avogadro.chem.iastate.edu/msds/acglac.htm


Part of that says "Acetic acid should be kept above its freezing point (62°F), since it will expand as it solidifies and may break container"
which is nonsense.
It does not expand on freezing.
It is easy to verify that fact.
if you partially freeze some the solid sinks in the liquid.

On the whole I'd keep the stuff at room temp. It stinks a bit, but having to thaw it when you need some is a nuisance.
Also, if you only partly thaw it you will end up with the impurities concentrated into the liquid phase so, the bottle might contain 99.5% acid, but what you get out will be rather less than that.
The fire hazard is a bit of a red herring for most of us. The flash point (39C) is well above room temperature.
Finally, when you take the cold bottle and open the top there's an opportunity for water to condense onto and into it. You don't really want that.

Tsjerk - 24-7-2014 at 02:20

I always kept it in the cabinet in a garage where temperatures fluctuated between -10 and 30 degrees Celcius. It was frozen and thawed numerous times, never had any problems with it.

I can confirm that AA does not expand upon freezing, if frozen in a bottle the solid will come lose from the glass and lose cylinder of frozen AA will form.

The Volatile Chemist - 24-7-2014 at 05:38

Quote: Originally posted by unionised  
Quote: Originally posted by forgottenpassword  
MSDS says that it should be stored above its freezing point. http://avogadro.chem.iastate.edu/msds/acglac.htm


Part of that says "Acetic acid should be kept above its freezing point (62°F), since it will expand as it solidifies and may break container"
which is nonsense.
It does not expand on freezing.
It is easy to verify that fact.
if you partially freeze some the solid sinks in the liquid.

That's probably true for the 99.7% acetic acid, but may not be true for lower concentrations, which would expand due to water content.

unionised - 24-7-2014 at 13:09

Quote: Originally posted by The Volatile Chemist  
Quote: Originally posted by unionised  
Quote: Originally posted by forgottenpassword  
MSDS says that it should be stored above its freezing point. http://avogadro.chem.iastate.edu/msds/acglac.htm


Part of that says "Acetic acid should be kept above its freezing point (62°F), since it will expand as it solidifies and may break container"
which is nonsense.
It does not expand on freezing.
It is easy to verify that fact.
if you partially freeze some the solid sinks in the liquid.

That's probably true for the 99.7% acetic acid, but may not be true for lower concentrations, which would expand due to water content.


The physical properties quoted in the msds make it clear that they are referring to the glacial acid.

The Volatile Chemist - 24-7-2014 at 13:45

Quote: Originally posted by unionised  
Quote: Originally posted by The Volatile Chemist  
Quote: Originally posted by unionised  
Quote: Originally posted by forgottenpassword  
MSDS says that it should be stored above its freezing point. http://avogadro.chem.iastate.edu/msds/acglac.htm


Part of that says "Acetic acid should be kept above its freezing point (62°F), since it will expand as it solidifies and may break container"
which is nonsense.
It does not expand on freezing.
It is easy to verify that fact.
if you partially freeze some the solid sinks in the liquid.

That's probably true for the 99.7% acetic acid, but may not be true for lower concentrations, which would expand due to water content.


The physical properties quoted in the msds make it clear that they are referring to the glacial acid.

Sorry, didn't actually look at it... So is this just conflicting info? Others say it doesn't expand...

Chemosynthesis - 24-7-2014 at 23:30

Quote: Originally posted by The Volatile Chemist  

Sorry, didn't actually look at it... So is this just conflicting info? Others say it doesn't expand...


Well, I thought it was the differential between the expanding glass and the acetic acid causing stress on the bottle, and a previously opened bottle having ventilation... but just maybe acetic acid's hygroscopic nature might have lead to the prophylactic advice as a generality.