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Q&As since 1989


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What material for lab hood for chromic acid and sulfuric acid?

We are in the process of building a new laboratory. In the new lab I will have one fume hood dedicated to cleaning with acid. The acids used in this hood are chromic acid, concentrated(98%)sulfuric acid as well as some dilute mixtures of sulfuric acid. The fume hoods in our current laboratory where acids were used are in horrible shape. The acid has corroded them significantly. The construction firm building our new lab is recommending 316 stainless steel for the acid hood. I didn't think this was a good choice but am unsure what to suggest as a replacement. Can someone give me a recommendation of a material from which a fume hood could be constructed or lined?

Ann Ferry
Laboratory Chemist - Sunray, Texas
2007

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First of two simultaneous responses --

The SS hood would probably be reasonably durable although I would consider one fabricated from PVC or fiberglass.
Also the blower should be constructed from similar material.

Gene Packman
process supplier - Great Neck, New York
2007

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Second of two simultaneous responses -- 2007

Hi Ann !

Firstly, go and have a gander at the fin.com first page.
There you'll see on the r.h. side # 4 ... ie. the on-line Library.

Hit 'library' and scroll down to plant and process engineering.

There should be some info to interest you.

Looking back in time, I'd opt for ordinary MILD STEEL but, say, min. 1/4" or 3/8" thickness for the hood, all ducting to be regular mild steel of welded construction. Never, ever use galvanized.

Scrubber? Yes, most definitely ! See the photo at the top of the page. That's an ordinary LMITS I believe ... the S-LMITS has a wider first stage as it contains two banks of blades. But if you don't see that photo, try Prolite.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).