Questions About Diethyl Ether Danger

[sekio]

In my ~10 years in working in a lab I've yet to see any diethyl ether peroxide form, I suspect it's only an issue for people who have astoundingly old reagents or are making their own ether and forgetting to stabilise it with BHT.

 

[Limpet_Chicken]

IIRC addition of alkali hydroxides to ethers doesn't actually inhibit the process of peroxide formation, rather, it precipitates the intermediate hydroperoxides, which are much less dangerous than the alkylidene peroxides. The hydroperoxides are reported as being less shock/friction/bad mood sensitive and to deflagrate rather than detonate. Still not a good thing to have happen in a bottle of ether, but at least if they were to destabilize under the ether, it MIGHT have less of an impact than with oxygen rich air available.

Still. Better IMO to prevent their formation than to trap the intermediates.

And not all ethers are so benign as EtOEt. DIPE is one of the worst. Supposed to be checked at min. 3 monthly. Diethyl ether yearly, to compare. Sekio-what are your reccomendations for THF? both inhibited and sans inhibitor?

 

[Pomzazed]

Well, yes i said inhibit “accumulation” not formation.

 

[Limpet_Chicken]

Still, I can't see that precipitating the hydroperoxides is a good idea. Think about it this way-they always say never to distill ethers to dryness, this is because it concentrates peroxides until the solution is concentrated enough to go 'boom' and blind some poor bastard with flying glass, or wipe out a ? 1000 rotovap. Or both if your really unlucky. It just strikes me as a bad idea to deliberately concentrate the hydroperoxides, even if they aren't as outright vicious as the peroxides, they aren't anything you want around.

Inhibition of formation is far better than just stopping the process of formation at the hydroperoxide. Don't forget they are still explosives. If only low explosives rather than supersensitive primaries with a hair trigger, its still an explosive, in a bottle of ether, one of the most flammable solvents around in most labs bar carbon disulfide.