My general recommendation is to use a fume hood. Extracting can be safe, but that largely depends on the how its done. DMF like many other good polymer solvents is toxic, so limit the exposure as much as possible

For safety, check MSDS of DMF and search for the MAC tresholds (maximum allowable concentration at the workplace). With your flowrates you can estimate the safety and which safety measures have to be taken and discuss them with your lab members.

And as an additional info/concern: there are laboratories that don't allow pregnant women to enter when/while DMF is used.

Thanks Mina and Marc!