Sciencemadness Discussion Board

Diethyl Ether Disposal

rrkss - 28-1-2010 at 21:19

What would be a safe easy way to dispose of some old unused diethyl ether (about 6 months old). Its about 100 mL of ethanol stabilized ether in an amber bottle. I don't have any peroxide test strips or KI in stock so can't do any tests for peroxides nor do I have FeSO4 to do a reduction.

Would it be safe to evaporate it outdoors in an iron pot or are more elaborate methods required?

[Edited on 29-1-2010 by rrkss]

bahamuth - 28-1-2010 at 22:06

As long as the Et2O hasn't been exposed to oxygen e.g. the flask not opened hundreds of times last six months I wouldn't worry..

Myself used up last 50ml of Et2O last month which was about 15 years old, but only opened about 25 times, and that in the last 5 years.


But remember, never evaporate or distill Et2O to complete dryness, if you follow that you'll be safe.

Picric-A - 29-1-2010 at 00:15

Burn it :cool:

Taoiseach - 29-1-2010 at 02:35

Great...

another "how do I expose of expensive and hard to obtain chemicals that most hobbyists will never get their hands on" thread.

I'm just waiting for "how do I dispose of 1kg red phosphorous" or "how do I safely dispose of 100g granular silver" threads...

Picric-A - 29-1-2010 at 03:03

Ether is neither expencive or hard to obtain. It can be made with materials more than readily available from a hardware shop (H2SO4 + C2H5OH) and is about £5 per litre.

woelen - 29-1-2010 at 03:23

Picric-A, what you are saying might be true for you, but in other parts of the world things may be quite different.

This kind of thread also irks me, especially if one is talking about useful reagents like in this case. If I really would want to get rid of a chemical, then I first would see if I could make someone else happy with the chemical. I have obtained quite a few chemicals, because someone else did not want them anymore and I am thankful that those people did not dispose of these chemicals by destroying them but were thinking of me :) .

Taoiseach - 29-1-2010 at 03:58

Well I can understand that potassium with a brick red crust causes some misgivings, but disposing of 6 months old ether is just plain BS. Especially since this chemical is very difficult/impossible to obtain in some countries and a lot of home chemists would love to get their hands on such a bottle.

>Ether is neither expencive or hard to obtain. It can be
>made with materials more than readily available from a
>hardware shop (H2SO4 + C2H5OH)

I agree (altough it is a dangerous procedure). Thats what this forum is about - making hard to obtain and exotic chemicals. Not how to dispose of them.

[Edited on 29-1-2010 by Taoiseach]

DJF90 - 29-1-2010 at 04:03

Picric A: I think you are greatly undervaluing ether. £5/L is a ridiculous price, and from what I've seen over many sources the general guideline is abour 3-4 times that price. Even if you were to make it you would not reach such an ecomomy; the alcohol required (even mineralised methylated spirits) costs about that. Once you factor out the energy needed to purify the alcohol, maintain the reaction at ~140*C etc it could even come out to me more expensive than available sources.

Chainhit222 - 29-1-2010 at 05:41

i would "dispose" of it in my lungs... i doubt many users here would approve though hehe

Picric-A - 29-1-2010 at 06:11

My local garage sells 1l bottles of tech grade ether for use as an engine starter for 5.99 each.
Maybe it would be 3x if you buy A.R grade ether but the fact of the matter is the tech grade is easy to purify to 99.9% so why bother.

DJF90 - 29-1-2010 at 06:19

Nope, AR grade is far more expensive, I was talking LRG, not tech, but nice find. Does this garage have a name?

Picric-A - 29-1-2010 at 06:21

Burnham garage :)

DJF90 - 29-1-2010 at 06:31

I dont think that that is even tech grade ether; the majority will be petroleum distillates, particularly those which pose a problem when trying to obtain pure ether. And all the engine starters I have seen are sprays.

Picric-A - 29-1-2010 at 06:38

Nope its not the kind you can buy in spray cylinders which containt <60% ether. This stuff evaporates to dryness and seemes pretty pure.
1 distillation over Na is enough to render it pure.

entropy51 - 29-1-2010 at 06:57

Quote: Originally posted by rrkss  
What would be a safe easy way to dispose of some old unused diethyl ether (about 6 months old). Its about 100 mL of ethanol stabilized ether in an amber bottle. I don't have any peroxide test strips or KI in stock so can't do any tests for peroxides nor do I have FeSO4 to do a reduction.

Would it be safe to evaporate it outdoors in an iron pot or are more elaborate methods required?

[Edited on 29-1-2010 by rrkss]
You can easily make FeSO4 by dissolving steel wool in strong CuSO4 solution with a few drops of H2SO4.

It is probably safe to evaporate outside, but if it contains peroxides they will concentrate and be sitting there after the ether is gone. Put a little FeSO4 in it before you evaporate it.

Bahamuth is correct in that there is no need to dispose of it just because it's 6 months old. I know that's what the books say, but if kept in a nearly filled and tightly capped brown bottle in the dark peroxide formation is slow in ethyl ether. Some of the other ethers are more prone to oxidize.

woelen - 29-1-2010 at 07:15

I have a bottle of diethyl ether (1 liter, filled almost completely to the cap with just maybe 20 ml of air trapped in the bottle) and this is around 10 years old (I purchased it for a just a few guilders before ether became unavailable at most places). No peroxides can be seen and I am not scared at all of this. I had another small bottle of ether (100 ml) and this was even older, but never had problems with peroxides forming in this. The only thing is that I do not use it in distillation setups without first destroying any peroxide, but in general, I think that the problem of peroxide formation in diethyl ether is highly exaggerated. I am talking about diethyl ether, I have no experience with other ethers, so the scary stories _might_ be valid for other ethers, but they are not true for diethyl ether.

rrkss - 29-1-2010 at 07:49

Quote:
[quote=170701&tid=13333&author=entropy51You can easily make FeSO4 by dissolving steel wool in strong CuSO4 solution with a few drops of H2SO4.

It is probably safe to evaporate outside, but if it contains peroxides they will concentrate and be sitting there after the ether is gone. Put a little FeSO4 in it before you evaporate it.

Bahamuth is correct in that there is no need to dispose of it just because it's 6 months old. I know that's what the books say, but if kept in a nearly filled and tightly capped brown bottle in the dark peroxide formation is slow in ethyl ether. Some of the other ethers are more prone to oxidize.


I'll make the FeSO4 the way you mentioned. I will get the iron in the correct oxidation state this way?

I used the ether for extractions of oils such as Eugenol and Limonene from emulsions after steam distillation. Its low boiling point allowed me to seperate the ether from the oil using a hot water bath instead of having to rotary evaporate it.

Since I am no longer doing that sort of chemistry, I don't need the ether and I see no reason why I should store a peroxide forming DEA List II chemical that I don't intend to use.

[Edited on 29-1-2010 by rrkss]

entropy51 - 29-1-2010 at 08:05

Quote:
I'll make the FeSO4 the way you mentioned. I will get the iron in the correct oxidation state this way?
Yes, it should be the greenish ferrous salt, but I believe it needs to be kept slightly acidic.

It sounds as though you could probably use dichlormethane for that sort of chemistry. It's safer than ether, but not good to inhale the vapors.

rrkss - 29-1-2010 at 09:54

[quote author=entropy51]
Quote:
It sounds as though you could probably use dichlormethane for that sort of chemistry. It's safer than ether, but not good to inhale the vapors.


I've substituted pentane as my solvent of choice though dichloromethane is probably another good alternative though much worse for the environment.

I'm gonna treat my ether with the ferrous sulfate solution you explained how to make and then let it evaporate outside to eliminate it in an iron pot with some paper towels. After the ether is gone, the towels go in the trash. Don't want to burn the solvent since there are regulations against that and ether has a half life of about 10 hours in the atmosphere so I would be not doing any real polluting. The pot is to eliminate ground absorbtion.

[Edited on 29-1-2010 by rrkss]

bahamuth - 29-1-2010 at 11:17

Half a year ago, some not so knowledgeable people at my faculty rotavapped 500 diisopropyl ether; that I found in a old cabinet hidden away, this bottle was opened in 78....

It was funny to watch them walk to their destined lab to evaporate the ether, with face shields, plastic aprons and leather gloves..., did I mention that the bottle had visible crystals in it, and a broken cap; either way, no explosion, they most likely added FeSO4 and some other chemicals to break the peroxides down.


Even so, they were kind of foolhardy doing stuff like that.

Never asked what they did to survive the event though...

itchyfruit - 29-1-2010 at 11:17

You can buy diethyl ether on ebay for about £15 per litre. So it can't be that hard to get and i'm sure it would be cheaper if you shop around.

rrkss - 30-1-2010 at 09:31

Ether is also easy to synthesize just don't use any open flame heat sources. I use a heating mantle for the synthesis from ethanol and a warm water bath for distillation after the workup. You can just use a bucket of warm water at about 45 degrees celsius to boil the ether, don't even need a heating source if you are doing it on a small scale.

An excellent procedure is available in prepublication explaining how to do it. After the synthesis, I add 1.5% anhydrous ethanol to my ether as a stabilizing agent.

[Edited on 30-1-2010 by rrkss]

entropy51 - 30-1-2010 at 11:03

Ethanol stabilizes chloroform against phosgene formation. I don't think it will stabilize Et2O against peroxide formation. Might be interesting to test some if you have any that's been sitting a while. Shake a few mL with a mL of AcOH containing about 200 mg of KI and see if it turns yellow or brown.

smuv - 30-1-2010 at 11:03

Ive burned some (say 250 ml) of ether, it is rather unspectacular, does not differ much from burning say hexanes, except the flame is much less sooty, and less yellow.

I say evaporate or burn it.

@Chainhit222 : Inhaling old ether, is really unhealthy. Ether in and of itself is not very toxic, however peroxides and acetaldehyde which contaminate old ether are toxic.


[Edited on 1-30-2010 by smuv]

rrkss - 30-1-2010 at 12:01

Quote: Originally posted by entropy51  
Ethanol stabilizes chloroform against phosgene formation. I don't think it will stabilize Et2O against peroxide formation. Might be interesting to test some if you have any that's been sitting a while. Shake a few mL with a mL of AcOH containing about 200 mg of KI and see if it turns yellow or brown.


Sigma Aldrich uses ethanol to stabilize some of their ethyl ether commericially. I assume the peroxides will be reduced when they oxidize the ethanol to ethanal which then bubbles off or could be further oxidized to AcOH.

http://www.sigmaaldrich.com/chemistry/solvents/learning-cent...

entropy51 - 30-1-2010 at 12:33

Thanks rrkss. That's good to know. It seems that EtOH wouldn't be good for Grignards though?

DJF90 - 30-1-2010 at 13:46

Nope but theres two factors to consider: a) Its only 1.5% and b) A good chemist will always distill his freshly dried solvent just before the reaction ;)

bahamuth - 30-1-2010 at 20:49

By the way, the KI method is only for extreme levels of peroxides, as far as I have experienced.

FeSO4 test is more sensitive if even if small levels of peroxides are present. Would use this any time over KI method.

Paddywhacker - 30-1-2010 at 23:47

re disposal

Model airplaners might buy it through an online auction. You'd want locals, to avoid having to ship it.

Or mix it into your petrol tank, or into 2-stroke fuel.

rrkss - 31-1-2010 at 09:00

No longer have the ether, but thanks for the tips.

smuv - 31-1-2010 at 14:01

Quote:
Or mix it into your petrol tank, or into 2-stroke fuel.


TERRIBLE advice! Ether will make a gasoline engine predetonate (knock).