# Preventing build-up of Diethyl Ether Peroxides

I've never stored Diethyl Ether before but am thinking of producing minor amounts myself and storing said Ether inside of glass/PTFE bottles.

I am aware of possible pressure build-up due to vapors and storage temperature, but what always puts me off is the formation of explosive peroxides.

Now as the above Wikipedia article mentions:

Diethyl ether hydroperoxide decomposes in the presence of sodium hydroxide and $\ce{Fe^2+}$ -containing salts.

This is obviously stating that I can stop the peroxide formation simply by adding in some $\ce{NaOH}$ which I have an abundance on hand. However that above information is regarding hydroperoxides. The less nasty of the two peroxides.

Ethylidene peroxides are the explosive ones that detonates by simply touching it. This is what scares me. There's no information regarding the stopping of formation on the page, and frankly my google searches for "Safe storage of Diethyl Ether" and "Stop Diethyl Ether Peroxide formation" seem to come up with "put some iron wire in it" or Potassium Hydroxide.

So my question is: what is the most reliable, safe, and long-term solution to prevent building up of both of Diethyl Ether's peroxides, especially the Ethylidene peroxide, with the least amount of contamination possible.

• Where does the wikipedia article say etyhlidene peroxide is not reduced with Fe2+? – Karl Jan 9 '17 at 4:36
• @Karl Well for me, the real question was, where does the article say it IS reduced? Nowhere. – finnrayment Jan 9 '17 at 4:40
• You state that iron salts like Fe2O3 should help. This is incorrect, since this contains basically Fe3+ only, which cannot reduce the peroxides (that's the manner in which the peroxides are rendered safe). Moreover, Fe2O3 is basically insoluble. In my experience, the canonical reagent for the reduction is FeSO4. – TAR86 Jan 9 '17 at 6:21
• @TAR86 Thankyou for the correction, far out I'm making some errors today! I did see somewhere that Ferrous Sulphate was the way to go but then again, I made this question for a reason. I'll edit it out. – finnrayment Jan 9 '17 at 8:01

There's no information regarding the stopping of formation [of ethylidene peroxide] on the page...

Diethyl ether peroxide, also known as ethylidene peroxide, [...] is a polymerization product of diethyl ether hydroperoxide

With other words:

If you prevent the formation of diethylether hydroperoxides by

• storing diethylether in a brown bottle over sodium hydroxide

you will automatically prevent the formation of subsequent products, such as the ethylidene peroxide.

Note that there is a different approach, which is recommended in terms of workplace safety:

Substitute diethylether with methyl tert-butyl ether (MTBE), which does not form peroxides.

• Ah, I didn't see the polymerization piece.... My bad. :P – finnrayment Jan 9 '17 at 4:42
• Why the hydroxide? – Karl Jan 9 '17 at 5:16
• @Karl If I remember correctly, the hydroxide deprotonates the hydroperoxide and renders it insoluble. – Klaus-Dieter Warzecha Jan 9 '17 at 5:28
• What if we just used Ethanol? – finnrayment Jan 9 '17 at 8:02
• @frayment What do you mean? Substitute diethylether with ethanol? – Klaus-Dieter Warzecha Jan 9 '17 at 8:18

The ethylidene peroxide is the polymerisation (polycondensation actually) product of the hydroperoxide. Firstly that only occurs when the solution gets concentrated, i.e. when the ether and residual water evaporates. Secondly, it is also destroyed by Fe(II) just as the hydroperoxide, and thirdly, you must store ether away from light anyway, and then you should never get peroxides. Have your peroxide test strips at hand and check from time to time, and IF they give a positive result, add the reducing agent.

https://en.wikipedia.org/wiki/Diethyl_ether_peroxide

We are medical lab doing occasional water:ether extractions. We have always had the practice of adding deionized water to diethyl ether, and drawing ether from the top of this stock. This apparently removed some minor impurities in the diethyl ether stock able to dissolve in water. I was taught this is a safer way to work with ether, but have never seen this mentioned in documentation from any supplier, such Sigma or any publication or educational text. We only have small amounts and try to not keep it around very long, so I have never been able to determine what the water addition does regarding peroxide formation over longer storage (years).