According to the August 27, 2007 issue of C&EN, page 29, the EPA says that the toxicology data on tetrahydrofuran show “suggestive evidence of carcinogenic potential”. The cited document can be found at this link.

It’ll be interesting to see what happens as a result of this study.  It is understatement to say that THF is a mighty important solvent. More than a few important processes require this cyclic ether.  Perhaps this is how Methyl THF makes its appearance to a wider audience?  But in doing so it will only attract the attention of toxicologists.

With REACH and the EPA’s reexamination of many substances in current use, there is likely to be an extended shakeup coming for US chemical processors in the next 5-10 years.  What the rest of us have to reconsider is what constitutes acceptable risk. It’s time for that old aphorism- “A ship in harbor is safe. But that is not where ships are meant to be.”

The hardest problems to deal with seem to be the low signal-to-noise ratio phenomena- low level radiation, low level pollution,  trace levels of this or that in the working environment.  Most likely, acceptable THF exposure levels will come way down and the material will stay in use. That’s my guess.