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Why not use galvanized metal kitchen tabletop?

I did pose a question early this yr. I had made a kitchen table top for a friend out of galvanized sheet metal years ago. I have heard some say not to use the galvanized but rather use zinc. I only ask again so I can better understand and explain the possible problems to my friend if there is a concern about using galvanized metal for kitchen table tops.

Richard De Troyer
hobbyist - Ann Arbor, Michigan
2005

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2005

Galvanized metal is steel that has been hot dipped into molten zinc and, possibly, subsequently treated with a chromate conversion coating.

Some people feel that even the zinc itself is a problem as a food surface -- http://www.icat.org.au/documents/cr-2002-09-GIbench.pdf

Obviously some don't, including me for what that's worth, and zinc is quite fashionable once again as a countertop surface.

But the other issue, and it is also addressed in the previously referenced '.pdf', is the chromate. Does the zinc have a hexavalent chromate conversion coat? It's not easy to know. And chromate should definitely not be used as a food surface. I have seen galvanized metal used in Lone Star restaurants, but only as a vertical surface, not as a counter top, and I have no idea whether they enforce a chromium-free requirement or not.

The problem really is that when one uses a material for a purpose for which it was not intended (and galvanized sheet wasn't intended to be used as a countertop), it's very difficult to know whether it is suitable or it isn't because you don't quite know what you have, nobody has tested and certified it, and you don't have enough other people doing it that any statistical history gets accumulated.

I would not make any more galvanized countertops if I were you, but I honestly have no idea what your friend should do because I just don't know whether there ever was any hexavalent chromate on the surface or not, and whether there still is. If it were in my kitchen--and this is just personal, it's not professional advice--I would probably carefully scrub it once with trisodium phosphate [on eBay or Amazon], then wash it a second time with vinegar [in bulk on eBay or Amazon] and water (disposing of the rags), and say "oh well".

You could write to "Dr. Galv" at the www.galvanizeit.org site and see if they have different advice.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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Ted, Thanks for your response to #36913 Galv.table top. I did ask Dr. Galv. And John Krzywicki he spoke of no known galvanize health hazard. But he didn't refer to the issue of hexavalent chromate conversion. I will ask him on that. I just want to redo the table with Zinkplate as I can get a letter of "material use".

Thanks again.

Rick De Troyer
- Ann Arbor, Michigan
2005