Mike,
We used to have a pretty efficient extractor over a perfussion table that
was built by our building management people. It consisted simply of a
canopy hood much like the ones you see over stoves,hooked up to the
laboratory  fume hood. The total cost was around $1,000. Another cheaper
option is to buy portable HEPA filtered air purifiers., in the U.S. a good
one will run approx. $250 and they work great. Also Surgipath sells
Formaldehyde neutralizing pads that you can place your specimens on and
will absorb  the formaldehyde and render it nontoxic (you can actually
dispose of them in the regular trash afterwards) these cost aprox $10 each.
Hope this helps, there is no need to breathe that stuff!
Alexis


Center for Transgene Research
and the
Department of Chemistry and Biochemistry
University of Notre Dame
Notre Dame, IN, USA
46556
219-631-3539 (phone)
219-631-4048 (fax)