Fume Hoods in Rad Labs -Reply

[FRAMEP@ORAU.GOV]

With regard to a fume hood in which P-32 and S-35 were to be handled
in 1 mCi quantities, Denny wrote in part:

>The architect is inquiring about specs for the fume hood, primarily
>material of the surfaces and ductwork.  My thinking is sheet metal
>of the normal thickness for ductwork.  Seamless would be great, but
>I don't whether that is cost effective or not.
>Any thoughts?

I already responded, but I've now located a copy of ANSI Z 9.2 which
gives the following minimum recommendations wrt sheet metal duct
thicknesses for transporting nonabrasive dusts:

diameter    gage U.S.

up to 4"     24
4 to 8"      24
8 to 18"     22
18 to 30"    20

Also, I had stated that I was partial to stainless steel. A couple of
folk have noted, quite correctly, that it might have corrosion
problems. We've never had such a problem here with our stainless
steel hoods  but we don't handle much in the way of halogens (e.g.
HCl, HF) which, as I understand it, are the main problems. 

I believe, the ACGIH "Industrial Ventilation" manual that was
recommended by several people including me runs ca 40-50 bucks and
can be had from:

American Conference of Governmental Industrial Hygienists
1330 Kemper Meadow Dr.
Cincinnati, OH 45240-1634

Note, it does not provide guidance wrt materials and thicknesses of
these materials for ducts/hoods.

There is also a self study workbook for this produced by Jeff Burton,
(not the ACGIH):
Industrial Ventilation Workbook
3rd ed. ISBN 1-883992-04-4
IVE Inc
2974 S. 900 E
Bountiful Utah 84010
call (801) 298 8996

Its a bit more expensive so if you're interested you might want to
get your employer to order it.

Again, best wishes

Paul Frame
Oak Ridge Institute for Science and Education
Professional Training Programs
framep@orau.gov