Hoods for Iodination

[TUTTLE.WILLIAM_III@FORUM.VA.GOV]

I need some advice from any of you out there who have hoods used for 
iodination.  We are going to build some new research labs, and have the
opportunity to include a radiological hood which could be used for 
iodinations.  Is there a manufacturer for hoods used for iodination?
(I know of special "boxes" to be used inside hoods, but I am looking at
the possibility of including the "filtration" in the main hood itself)
Also:
1.When using a charcoal filter, should a prefilter be used? Does a HEPA
  filter make sense?
2.How do you test the charcoal filter?
3.How do you determine when to test the filter?
4.What environmental factors determine the usable life of the filter?
5.What are the airflow specifications for the filter?
Thanks in advance for your responses, please send them to me directly
unless, in your opinion, it is useful information to the whole group.
William K. Tuttle III,PhD,RSO, VA Med.Ctr.,Portland,OR
tuttle.w@portland.va.gov