Isopropyl Ether (Into the high, explosive, ether)

I love old bottles of chemicals, and I've spent many a diverting hour perusing the shelves of old university faculty members' labs. Bottles used to come in pounds (or giant "ONE MOLE" sizes). Faded typewritten text, "For medical, pharmaceutical compounding, or research use" labels, yellowed paper - Korean war-era bottles are about as romantic as bottles of chemicals get.

When it's old ether, though, I get away and make a note to warn someone (and not come back anytime soon).

Ethers - chemicals of the general formula R-O-R', can form peroxides (R-O-R'-OOR'') at the carbon adjacent to the ethereal oxygen upon reacting with atmospheric dioxygen. It has to do with the stability of the radical formed, so methyl ethers (CH3-O-R) and t-butyl ethers are pretty safe (part of the reason for the popularity of MTBE. Ethyl ether, THF, and dioxane have reactive protons. Even more of a peroxide risk is diisopropyl ether, which, due to the additional substitution, can form a very stable radical and is especially prone to peroxidation.


You can check your ether for peroxides quite easily (again, be careful, and you're probably better off throwing the truly old stuff away). Peroxide is a fine oxidant and will take iodide to iodine. Take up some KI or NaI in acetic acid (100mg/mL), mix 1mL with 1mL ether, shake, observe. Yellow=some peroxides, Brown=call your waste people now and set that thing aside. Careful handling old ether - if it's questionable, throw it out, it's not expensive!

If you must, I am told you can strip peroxides from ether on silica or alumina. I don't know if this works with the more hazardous alkyl peroxides, which are less polar than the hydroperoxides. There's also iron salts, sacrificial reducing agents, redistillation, and the like. Why bother, though? You've just concentrated the peroxides on a solid, and you still need to destroy them somehow. Just get rid of the stuff.

Like syringe exchange programs, universities should operate ether trade-in programs to keep people from acting like idiots with old solvent.

Ether peroxides terrify me. However, the risk is obviously pretty low - not many people see them go off, and a lot of people have laughed at me for being cautious with a ten-year old bottle of dioxane. Usually the same people that smirk at safety glasses. These aren't dumb people, either...

For some pictures of peroxide crystals, see here. If you see such crystals, get far, far away, call the appropriate people, and don't come back until someone you trust promises that hazmat blew 'em up on site.

Share your lab accidents/unusually cavalier colleague stories below!


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Fuck them then. Ether peroxides are nothing to take lightly. Perhaps they also use copper tubing with acetylene?

I take it that opening the window, waiting until the area under the window is empty, shouting "BOMBS AWAY!", and tossing the bottle out is not recommended practice?

Having just barley passed my Chem. 101 class (so theres my get out of being called a dufus card) Is this the stuff they use in Rocket fuel or something, so it must be taken seriously? I think i handled some of these bottles and was never told anything. I did wear my safety glasses though.

By Jonas Nepenthe (not verified) on 12 Aug 2007 #permalink