Best before...

[Rhodium]

My new bottle of Fisher ethanolamine says "Use within five years of opening". What happens in november 2007? It goes bad, and begins to smell even worse?

A Fluka bottle of DMSO I have tells me to pour it in another container after storing it in the original packaging (HDPE, I think) for five years. Those five years are up any day now. Will the bottle leak when it thaws up in the spring, or what?

[quixote]

[Rhodium]

Yes, that's pretty obvious, but to what does it degrade and why? Its not like it is a common marking on chem bottles (unless being peroxidizable stuff).

[raffike]

I think after that period,the contents is still usable,but isn't the same as marked/guaranteed on the label.Anyway you have 5 years to do something with that.Raf ordered some NaCN and CH2CH3NaO from Fluka
A friend with speed is a friend indeed

[quixote]

Well, with the ethanolomine the question is whether they assume that youll be opening the bottle periodically, and if thats not the assumption then perhaps photo degradation or more likely it starts doing funny stuff with the plastics. its suposed to be stable so I'd assume that it wouldnt be changing on its own...although five years is a long time.

And for the DMSO...are you asking how it deocomposes the plastics?

Raffike thats pretty much what I said, perhaps not realizing that the question is merely a curiosity and is not a question pertaining to the functionality of said chemicals in any procedure. Rhodium MUST know that in all likelyhood that chemicals would be usable for many many years, but that the labeling is perhaps an overprecaution?
Which in fewer words is what I basically said the first time.

[Rhodium]

Yes, I'm very well aware that I can store the DMSO in that bottle for 6 years, and that I will still have ethanolamine in the other bottle after 6 years, I was just curious as to WHY they have added these extra precautions. If HDPE is not stable to DMSO, then why package it in HDPE? What is the decoposition products of ethanolamine?

Five years is not a long time when it comes to chemicals. Well over half of the chemicals in any laboratory is over five years old.

[lugh]

Well over half of the chemicals in any laboratory is over five years old.

Which explains exactly why the package now states that the chemical is best used within five years, the wonderful world of mass marketing has come to scientific products    If the customers replace a small percentage of the chemicals due to this nonsense, then the company profits handsomely  

[ballzofsteel]

Shheeeeesh

And people bust ballz for naming a brand of matches or pills

How much dose fluka/fisher sell tincture for?

[Barium]

They don´t sell 'tincture', they sell the pure stuff
Catalytic hydrogenation freak

[hermanroempp]

The "best used before" on the label of has something to do with GLP/GMP and the manufacturers liability for the quality of his product. As already stated before in this thread, the ethanolamine will still be useful after 5 years (mine is over 10 years old and I have no concerns about using it), but the purity of the product will not be the same the brand new ethanolamine had. So the manufacturer simply tells you that this aged product may not be suitable for use when working under strict GLP/GMP conditions, that's all. Another purpose of this "best used before" term is that of a disclaimer for the warranty of the manufacturer, so that you can not sue him for failures which occurred due to the use of this over aged product.
I bet something about this can be picked up in the FDA regulations...
Quidquid agis, prudenter agas et respice finem!

[quixote]

Ethanolamine is certainly hygroscopic but is quite stable nevertheless (see

http://www.sigma.sial.com/sigma/proddata/e9508.htm

.  I've noticed that some of our liquid amines slowly darken after opening, even when stored in the dark, perhaps due to slow formation of polymeric degradation products after exposure to the air.  Triethylamine, on the other hand, is much more stable.  I have some ancient triethanolamine that still looks fine.
 
The bottles of DMSO I've always had were made of glass.  Maybe long term exposure of even polyethylene to some solvents leads to slow degradation or softening of the container.  This apparently happens to PVC (see

http://www.loganclaypipe.com/reactive.htm

) but with chlorines present this is obviously a polymer with much greater reactivity.
 
Steve