[staceyjyr]

I was just advised that we have some bottles of diethyl ether and THF in our chemical storage bunker.  Apparently this stuff has been there for about 10 years and due to the temperature fluctuations it has been exposed to temperatures around 35 degrees C.  Is this dangerous?

[Vidya]

Ethers are major source of fire hazards and are volatile in nature.One needs to be very careful as  it can be in vapor forms in the bottles .It does not require a source of ignition such as a naked flame, or spark to initiate combustion and can catch fire even if it is placed near a hot plate or if there is fluctuation in temperature.                                       

[Dan]

Is this dangerous?

Potentially. You can test them for peroxides with peroxide test strips (e.g. Quantofix), but if they are that old they should really be disposed of.

Some guidelines and references can be found here, which recommend disposal after 1 year.