Dear Ms. Baum:

Thanks for the reply. I am with the maj ority and I am against using “ductless” fume hoods (those hoods that do not have exhaust to outside but contain an integral exhaust blower and filters which do not require duct or venting to the outside).

Due to the cost factors I was asked by my company to gather information regarding these “ductless” fume hoods and th eir possible use. So far the comments indicating the safety issues using th ese type of the hoods with hazardous chemicals. I am trying to gather enoug h information from experts to convince my superiors against using these hoo ds.

Regards,

Michael

From: DCHAS-L Discussion List [mailto:DCHAS-L**At_Symbol_Here**list.uvm .edu] On Behalf Of Janet Baum
Sent: Wednesday, September 2 1, 2011 11:24 AM
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Subject: Re: [DCHAS-L] Fume Hoods

 < /o:p>

Dear Michael, Do you mean ductless fum e hoods, i.e. recirculating air fume hoods? There's a huge difference in th e IH capabilities between "ductless" and "ducted" fume hoods, if both are installed correctly. There are many IH risks and QA/QC c onsiderations in using ductless hoods. Do you have documented and compellin g reasons to consider using ductless hoods?