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Author: Subject: Handling of diethyl ether
testimento
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[*] posted on 1-10-2013 at 03:10
Handling of diethyl ether


I would like to have some advisory on handling ether properly. What factors could be used to minimize the vaporization of the solvent during process? I have thought of following methods:

-Using PTFE tubing to pour and drain solvent instead of open pour into funnel
-Minimizing the ambient temperature via conditioning or climate
-Using only closed vessels or installing a plastic foil over the equipment
-Keeping the liquid as cold as the reaction and conditions allow

-How effective is activated carbon filter to remove the vapors and odors of ether? I have found few sources that cite it is "2/3" or "3/4"), but I have conflicting empirical data, when I used respiratory mask with AC packing, quite a lot of smell came through directly. Dont know wether this is due to the relatively high concentration or due to the limited absorption, therefore, maybe using stationary ACF 2-3x larger than the line-fan capacity, might do the job.

http://www.islandcleanair.com/pdf/Activated%20Carbon%20Expla...

http://www.sentryair.com/activated-carbon-filter.htm

[Edited on 1-10-2013 by testimento]
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Ascaridole
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[*] posted on 1-10-2013 at 17:44


When working with air free glass we use a cannula, essentially a double ended stainless steel needle ranging form 12-24" in length. However when using a cannula the system is never truly "closed" a glycerol bubbler prevents dangerous over pressures and ensures a constant flow of inert gas. As for the respirator if you can smell ether vapors you probably have a fire hazard on your hands. Proper ventilation to ensure no ether vapors are allowed to fill your work space is the best bet.
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Pyro
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[*] posted on 2-10-2013 at 11:01


if you have ventilation and the temperature isn't too high you shouldn't worry.
what do you intend to do with it?




all above information is intellectual property of Pyro. :D
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sonogashira
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[*] posted on 2-10-2013 at 13:36


Put your nose into the bottle and breathe very deeply. ;)
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MichiganMadScientist
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[*] posted on 2-10-2013 at 15:33


Diethyl ether is just one of those solvents that is very strong smelling, even if only a small amount of it is exposed to a working evironment. I actually find the smell to be pleasent, but I would never advise working with it in an unventilated area, primarily due to fire hazard..
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cal
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[*] posted on 3-10-2013 at 03:41
Ether


The main problem with ether is that it will spontaniously combust when mixed with the proper amount of air. I have a vent hood and wear a gas mask and run my bubbler tube up to the edge of the exhaust with a clip to ensure the vapors go directly into the exhaust fan. With these precautions I have had no trouble with ether running Grignard Reagants.



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confused
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[*] posted on 3-10-2013 at 05:28


are you sure about that?
the autoignition point of ether is 160'c it wont spontainiously combust untill it reaches that temperature
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[*] posted on 3-10-2013 at 06:31


Quote: Originally posted by cal  
The main problem with ether is that it will spontaniously combust when mixed with the proper amount of air.
As confused suggests, this is incorrect.



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testimento
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[*] posted on 3-10-2013 at 06:49


Indeed it is. Ether will not spontaneously ignite, but it certainly does it at very low temperatures(some sources cite 120, some 160 degrees C) or from very low static electricity sparks with quite a wide range of air-fuel-ratio of about 1.9-48% mixtures, meaning, absolute concentrations between 20 and 500 grams per cubic meter can ignite (if air D is 1.25kg/m3 +-0.1kg). This can be prevented effectively by handling ether in closed apparatus, but the odor threshold is 0.33ppm, so technically, as long as there are traces of ether in air, one can smell it.

Ether isn't quite that dangerous and it has even been abused, and I wouldn't use respiratory solely for security if no other hazardous chemicals are involved, but an effective ACF filter is required to prevent the ethereal fumes from exiting the workplace, since I have no industrial flat with overhead exhaust available.
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watson.fawkes
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[*] posted on 3-10-2013 at 07:40


So much confusion here. There are two concepts at play here, both eventually involving flame. The first are the flammability limits , the lower explosive limit (LEL) and the upper explosive limit (UEL). This represents the percentage range of fuel-air mixtures that will ignite with an ignition source. The second is the autoignition temperature, which is a temperature at which a fuel will spontaneously combust without an ignition source. This is typically quoted for ordinary atmospheric pressure and composition.

For diethyl ether these figures are as follows. One of the reasons that it has a reputation for hazard is that the UEL-LEL range is rather large compared to other solvents, combined with its high vapor pressure at room temperature.
  • autoignition 160 °C
  • LEL 2%
  • UEL 36%
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[*] posted on 3-10-2013 at 07:44


i have an idea actually..
you could perhaps take a bottle, then install a little 'water tap' so that you can open and close it, like a water tap (probably have some sofisticated name)
you could fasten a cylinder to this to make it capable of standing upright, if this would be nessecary..




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[*] posted on 3-10-2013 at 07:52


I have an efficient fume hood and with some awareness can avoid offending the mailman or others out walking in the vicinity of my house. I still very much dislike using ether as it stinks up my garage even with the use of my fume hood. Plus, one must be extraordinarily careful regarding the fire/explosioin hazard.

I am at this time in the process of preparing to run a Grignard. This means I first have to obtain my ether via fractional distillation from the CO2, propane, and heptane in starting fluid*. Lately I have been wondering if the use of tetrahydrofuran (THF) would work just as well yet have a much less offensive smell?

*(Someday I must travel to Australia just to see a can of "Start You Bastard! ;). )

[Edited on 3-10-2013 by Magpie]




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kristofvagyok
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[*] posted on 3-10-2013 at 10:39


Quote: Originally posted by cal  
The main problem with ether is that it will spontaniously combust when mixed with the proper amount of air.
This is simply not true. We have made experiments with a few "dangerous" solvent. We poured a little in a beaker, than placed a lighten cigarette over it and started to "smoke it" by connect it to vacuum.

Diethyl ether, THF, methanol didn't do anything, only the CS2 started to burn.

Quote: Originally posted by cal  
I have a vent hood and wear a gas mask and run my bubbler tube up to the edge of the exhaust with a clip to ensure the vapors go directly into the exhaust fan. With these precautions I have had no trouble with ether running Grignard Reagants.
<span style="text-decoration: line-through;">Pussy</span> I would highly recommend computational chemistry for you.

[Edited on 3-10-2013 by kristofvagyok]




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testimento
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[*] posted on 6-10-2013 at 16:13


A promising test for ether fumes. I opened a canister of ether in a warehouse and due to slight pressurization of the vessel a strong ethereal smell immediately spread through the room. I placed a 1500m3 rated activated carbon filter and a line fan sucking air through the fan, and put it on the floor and as we all know, ether fumes tend to fall down, and started the fan. Within a minute, the room air had purified completely from the etheral smell, and I even soaked a small rag in ether and placed it next to the filter and smelt the fan air and I smelt nothing. I have to perform larger scale testing later when I get the fume hood all packed up.
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[*] posted on 8-10-2013 at 02:25


I have a somewhat off-topic question about ether:
From the post above, I gather everyone is "playing happily and merrily" with ether, but what about the oxidation products ether is said to form slowly when exposed to air?

I have a bottle of ether, some three years old, once opened, but still full. It has always been stored in a dark bottle in a closet around RT. The bottle does not contain any KOH and the label says nothing about the presence of peroxide preventors. Is it safe to pour a bit of this ether in a testtube and add a bit of KI to test for peroxides?
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[*] posted on 14-10-2013 at 13:24


If the ether appears to have evaporated be careful. Even inhibited ethers can form peroxides in the cap threads if left alone for a long time. Most commercial diethyl ether bottles are metal to help retard peroxide formation in addition to BHT. At least that's what I was told by my advisor who worked with diethyl ether and isopropyl ether for years.
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