The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Health hazards of galvanized steel benchtops-zinc flaking off

Dear friends,

I would like some information about any negative health impacts associated with the use of galvanized iron for kitchen benchtops or food preparation surfaces in the wet areas of kitchens. Does anyone have any bibliographic references which show that zinc surface coatings can corrode due to food spillage or acidic water (I am thinking of tomatoes and the like)? An Indigenous Australian community at Yuendumu in Central Australia is using galvanized iron for kitchen benchtops. This is actually permitted according to the Australian Northern Territory government's document "Environmental Health Standards for Remote Communities in the Northern Territory". We would like to see these standards changed and are trying to gather some documentary evidence to support our case. We are concerned that the use of galvanized iron for kitchen benchtops could lead to zinc poisoning. Any information about the health hazards of zinc/galvanized iron in contact with water or food would be gratefully received.

Have a lovely day.

Regards,

Patricia Morrow
Centre for Appropriate Technology - Alice Springs, NT, Australia
2003

---

Hi Patricia. I hope you're gathering information first and deciding if the application is unsafe based on what you find rather than the other way around. But you were being brief and I probably misread you.

I recently toured "The Breakers" in Newport, R.I., built for Cornelius Vanderbilt in 1893 and famous as perhaps the most exotic residence ever built -- and I noted that the food preparation surfaces were sheet zinc. So zinc food preparation surfaces have been around for a very long time and not for reasons of economy. But that doesn't make them safe, of course.

What would concern me most is that cadmium and zinc are mined together, look similar, and are often plated in the same shops. Sometimes zinc anodes and cadmium anodes are even accidentally interchanged. And cadmium is amply proven to be a powerful cumulative poison with effects on the body similar to lead or mercury. So even if zinc surfaces were found to be safe I would still worry about possible contamination by cadmium. Plus, galvanized surfaces are sometimes treated with a solution of dilute hexavalent chrome.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003