Sciencemadness Discussion Board

Phenol Storage

Mailinmypocket - 29-8-2012 at 16:30

I received a couple bottles of phenol crystals recently and it came in some poly bottles like the one pictured below. The phenol has a consistency similar to slightly wet snow.

Are the very hygroscopic phenol crystals going to go bad in a container like this? They are air sensitive and very hygroscopic, they literally melt in the air while I watch... The bottles have no indication of what kind of plastic they are made of either, so I don't know how permeable to air they are. They do close very tightly though.

I could transfer the bottles into something else...only if needed though because in this weather it gets wet fast, is already clumpy and sticks to the walls of what it is in...

Should I transfer it to something made of glass? Do any of you keep phenol in plastic?


phenol.JPG - 115kB

[Edited on 30-8-2012 by Mailinmypocket]

kristofvagyok - 30-8-2012 at 07:39

Quote: Originally posted by Mailinmypocket  
Are the very hygroscopic phenol crystals going to go bad in a container like this? They are air sensitive and very hygroscopic, they literally melt in the air while I watch... The bottles have no indication of what kind of plastic they are made of either, so I don't know how permeable to air they are. They do close very tightly though.

Should I transfer it to something made of glass? Do any of you keep phenol in plastic?[Edited on 30-8-2012 by Mailinmypocket]

Khm, phenol is absolutely not hygroscopic.

If the crystal melts, then they simply melt and not absorb water. The mp. of the phenol is low (40 Celsius), this is why it could easily melt.

Also: long ago they usually sold phenol in a molten form in a large dark bottle, because in this form just a little part of it was exposed to air. If anyone wanted some of it, the bottle was just placed in hot water and the liquified phenol was poured out.

And phenol could be stored in any well sealed container, even plastic or glass.

Mailinmypocket - 30-8-2012 at 09:24

Weird, everywhere online has mention of it being hygroscopic...

Why would it liquify at the temperature I was observing it at though (~26c)?

But if it will be okay in plastic I will just leave it there... or maybe put some in glass and leave the rest in plastic and see how it fares as a test.

Dr.Bob - 30-8-2012 at 19:20

The MP may be lower if not very pure, so it might easily melt if held in your hand for a short time.

Phenol should be pretty stable, so I don't see any issues with storage. I can't think of any way that phenol should react with air or water, even if it were to absorb some water it could likely be dried by putting under vacuum for a while. I have used bottles of phenols that were years old with no problems.

woelen - 30-8-2012 at 22:08

I have other experiences with phenol. It turns red on contact with air. Not at once, but over the years, the colorless crystals go from pink to deep red and they liquefy. I even had some phenol which is a deep red liquid, with long needle-like crystals of them in the liquid.

Maybe it is not hygroscopic, but it can be oxidized by air and the oxidation products have a strong color. Tyhe impurity then lowers the melting point of the phenol and that most likely causes the liquefying even well below 40 C.

I store my phenol in a glass bottle with a teflon-lined thick cap. I also had some in a plastic bottle, very similar to the one shown above, but I did not like it. My whole lab started smelling of phenol and in the long run that really irked me. The phenol seemed to go right through the plastic! It only is a VERY small amount which escapes like this, but people can smell phenol very well, so you easily get a smelly room. Since I have stored it in glass, the smell is gone.

Endimion17 - 31-8-2012 at 03:01

AFAIK, phenol creates two solutions with water. Coloured oxidation products as surface phase are probably the cause of initial "melting on air", which speeds up at elevated temperatures and relative humidity levels.
The first solution is solution of water in phenol, and the second is solution of phenol in water. The first one is responsible for turning to pinkish-red goo.
That's why when you stuff pure phenol in water to make yourself a saturated solution, solid phenol quickly disappears and two layers form, both in liquid form.
Anyway, I'm not entirely sure about all this, and I'd like someone to back me up, or correct me.

BTW here's a ship with an interesting name. :)

Mailinmypocket - 31-8-2012 at 04:56

Thanks for all the answers! I have decided to just transfer the whole lot into a glass reagent bottle because just like Woelen mentioned, I have noticed a smell of phenol growing over the last couple of days. When I smell the bottle the odor is definitely coming through the plastic. I love the smell of phenol but I don't want my apartment to start smelling "chemically" to others...Good to know it isn't hygroscopic though.

Endimion: Somehow that ship suits the name "phenol" lol