Toxic effects from galvanized food preparation utensils

A. A heat/flame dispersion plate is clearly not a food preparation or storage surface where food acids or biological activity could dissolve zinc into the food, Jeff. And galvanized metal is used in all sorts of hot applications which offer some limited potential for people inhaling fumes: automobile exhaust systems, hot ash cans, exhaust flues for furnaces and water heaters, electrical light fixtures, etc. I would certainly expect that the hardware used to assemble the hot areas of a propane or charcoal grill would be zinc plated.

If you don't want to use the grill and you want your money back, just take it back. If you are concerned over the public health, this particular one I would classify as de minimus :-)

A do-it-yourself smoker might possibly be a bigger issue due to the possibility of inadvertently using cadmium plated metal or hexavalent chromated metal, but personally I don't think there is any reason to continue to be concerned about this propane grill, Jeff. If I have misunderstood, please clarify. Thanks.

Q. Thanks for the speedy response, Ted! Well I am mainly concerned due to the effects I have heard from welding galvanized metal. Anytime you heat steel there is some gassing and obviously welding galvanized steel is going to cause some really nasty vapours, which contains some zinc, (nitrate), or so I have been told by some welders.

I guess my question is, if galvanized steel is heated to the point where "heat staining" occurs, are these vapours harmful? Can then these vapours deposit zinc nitrate onto food in an enclosed vessel, like a barbecue? Your answer, I gather is likely "yes, but not to any extent to be concerned about."

I am not attempting to de-bunk the galvanizing or plating industry, as my inquiries are based upon university research which has shown that the possibility of zinc poisoning from an item such as the one discussed may be much greater than previously suspected. Due to advances in bioreactive research technology, many items which were once considered safe, are now unavailable to the public.

I imagine that there are varying levels of sensitivity to suspect products from person to person, and to avoid many or all of these products would be impossible.

I appreciate the response and industry-based opinion, and of course, the mindful and candid manner in which you remind readers that there should be a "point" to questions, which I sometimes forget. Thanks Ted!

A. I'm getting old, Jeff, but within my lifetime it was considered medically essential that water never be put on a burn, only butter and other oils. And I can remember when manufacturers of breakfast cereal were hauled before Congress and lambasted by the media for subverting our children into a habit of eating the "empty calories" of whole grain and fiber for breakfast instead of wholesome protein like bacon and eggs and liver. Where are we with female replacement hormones -- good or bad? It's changed at least 3 times in 6 months. After half a lifetime of intensive study, is aluminum linked to Alzheimer's or not? Sorry, debatable. Mammograms good or bad, an alcoholic drink a day good or bad, coffee good or bad, milk good or bad, plastic butcher blocks an important replacement for cracked wood surfaces or an oleophilic surface that guarantees contamination?

We are a paranoid society which places far too much belief in the sketchiest of theories as long as they're scary enough (Toxic Timebomb in Your Kitchen! - News at 11); they are all instantly accepted and rarely demonstrated. But if Diet A is labeled worthless and diet B a healthful life style, then the positions reversed, back and forth, almost every other month, and we can't decide whether the carefully monitored things I listed above and ingested daily are good or bad for us, shall we honestly worry about very casual exposure to heated zinc?

What shall we make things of? Better not use aluminum! Steer clear of nickel! Don't use zinc! Copper and silver are powerful biocides that must be avoided. Rusty bare steel, forget it! Chrome? Don't be crazy. Concrete? Silicosis. Wood? Harbors bacteria. Vinyl? Carcinogenic vapors. Asbestos? Get real. Is cobalt safer than nickel? Probably until diets A and B reverse places.

We need to watch the biggies which it is hard to argue the dangers of: mercury, lead, and cadmium. And keep our eyes open for a fourth baddie, and maybe then a fifth. But our government throws wheelbarrows full of money at beltway bandit "researchers" in return for disproportionate campaign contributions (clever racket), who have been on the road of diminishing returns for decades, looking harder and harder for the slimmest of possible risks to scare us to extend their grants; our politicians make hay "protecting" us from the specter of toxic hobgoblins; and the TV networks keep us watching by warnings of impending calamity. Only an opinion.

A. Bleedin' 'ell, Jeff !

You are only going to get (some) fumes from normal metal products when you go to welding temperatures ... and the welding temperatures are WAY, WAY, WAY higher than a little ole flame or two in a barbecue.

Heck, why not say, ah, Teflon coated frying pans should be forbidden because when you heat Teflon you generate fluorocarbons. True but false. True if the temperature is excessive such as welding around 1300 °C, false if you use if for everyday normal cooking.

Ted's answer was very good INDEED....

Worry not ... nor should Dheerah worry about his so-called steel rust fumes. Just go and enjoy your steam bath ... probably much safer anyhow than bathing in the Ganges, eh?

Hey kids! Well I see the subject did continue on for some time. I have been really busy running a stainless steel sales/ manufacturing/ finishing business, but I did have time to experiment with my barbecue!

My findings are that indeed the piece of galvanized steel AND the other surrounding metal both created some acrid, smelly fumes for about 20 minutes during the first ignition.

After that, all I could smell was some tasty burgers, steak, and wild salmon. My conclusion? Well I'd say light up your new equipment and let it heat up real good once before you toss your fine meats on it, and let your nose be the judge as to when it's been heated long enough. Mmm...I love science!

I hope this will officially conclude this stream and save Ted from having to answer it anymore, because it is silly.

Jeff@HoleJoy!;)

Who says scientists don't have a sense of humor? I stumbled onto this thread wondering whether it would be safe to use galvanized hardware cloth (aka screen) to contain small pieces of "real" charcoal in the bottom of my large, black, tripod-legged, kettle cooker.

My hypothesis is that Jeff's approach will work well for me eliminating whatever harmful fumes might otherwise be discharged.

Thanks, everyone!

A. Hi, John.

As you can see from the above, we all have to draw our own lines when it comes to minimal exposures. I probably wouldn't build a pig roaster like this out of galvanized metal because I'd be worried that the material was misidentified and the plating might be cadmium. But that's just me, and I wouldn't argue with someone who felt it was perfectly safe.

A. Hi, Tony. I seriously doubt that anything you find in a hardware store these days is cadmium plated. Zinc is not toxic; in fact, it's a vital micronutrient, and cold prevention lozenges are zinc compounds. Welders face a special problem in that they vaporize the zinc and then inhale a large overdose.

Regards,

A. Dear All

Go to the "Fact Files" section of the European General Galvanizers Association site at www.egga.com and it will give you the information you need about service conditions for galvanizing.

You can find extensive toxicity info at www.iza.com, the site of the International Zinc Association.

A. Galvanized wire is probably not a good idea. You should use stainless steel wire, Katherine.

A. Galvanized metal is not solid zinc, but steel with a zinc coating -- so it may eventually rust. What would also concern me is the effects on the looks of the counters of acidic foods like vinegar [in bulk on eBay or Amazon], lemon juice, and tomato juice. They will attack it, and your counters will acquire a "used" look with different shadings from such exposures.

Some people worry about food contamination (www.icat.org.au/documents/cr-2002-09-GIbench.pdf, for example) but I personally felt that report rather silly and wouldn't worry about it myself. Zinc countertops are widely used and have long been. I visited the grand mansions of Newport last year, and in the grandest of them all, The Breakers, the rows of food preparation and cutting counters were all zinc if I recall.



What was good enough for Cornelius Vanderbilt would be good enough for me :-)

Hello again.

Thank you so much for your quick response regarding galvanized steel countertops. I agree that if it was good enough for Cornelius' home, it's good enough for me. (I'm sure my humble little house would fit in a Breakers' closet.) Thanks again!

You must have read too quick and thought that was my house in the picture four posts above yours, Karen -- because no one else has flirted with me in about 20 years. But I do have a son who's single and I think he'd be impressed with your pic and your ways :-)

Galvanized items, which usually can be identified by their shiny "spangled" look, are not suitable cooking surfaces. Wrapped in foil your turkey would be fine, so if you've already done it, save a drumstick for me.

But I don't think a galvanized pan should be used in an oven as a rule, because they are not designed for that function;  and it's always difficult to predict all of the possible consequences when something is used in an unintended way and we consequently don't have a rich history of experience to guide us.

A. This thread is growing long and repetitive, but my own personal comfort level is that I would use such galvanized lath to hold the coals in a homemade grill, but I would not put the food on it. For that I'd use stainless steel, or nickel plated or ceramic coated grates.

A. That should not be done, Janet. See web1.msue.msu.edu/imp/mod01/01600817.html. I know nothing of bakery equipment but am confident that such pans are available tin plated or of stainless steel construction.

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Ed. note: Sorry that MSU link is now broken

A. Sorry, Carrie, but no, it's not okay. Zinc is not supposed to be used as a cooking surface for food.

A. Hi, Jim. My guess is also that it's galvanized, although I suppose it could be tinned. Zinc is not a toxin, it's an essential micronutrient. The danger is in overexposure/overconsumption. I'm just a metal finisher, not a dietician, but my understanding is that there are three paths to that overconsumption:

1. When welders weld galvanized materials without adequate ventilation, vaporizing the zinc and inhaling clouds of it.
2. When acidic foods dissolve some of the zinc that they are touching and it is ingested.
3. When galvanized tanks and piping are used for water collection and storage.

I know that the first case of overexposure is very real, and we have several threads on that topic on line here. Regarding the second case, I know that government bodies consider zinc to not be a "food-safe" surface, but I'm not personally aware of actual issues from this. Regarding the third case, galvanized materials were used for water service for decades, but I think they no longer are in the USA; certainly they are still used in the third world and for livestock feeding and watering.

I don't think there will be any problems with your application, beyond breaking a finger if the top half of this heavy tank pivots down suddenly :-)

Regards,

A. Hi, Shari. There are lots of people building galvanized countertops and solid zinc countertops. Still, the government doesn't consider zinc to be a "food-safe" surface, and I certainly can't say "listen to the countertop builders and ignore the NIH" :-)

But unless your toddler is constantly eating sliced tomatoes from the bare countertop, I think the issue is de minimus.

Getting good adhesion of paints and clearcoats on galvanized steel is notoriously difficult, and you don't want your toddler eating paint chips, so I wouldn't coat it.

Regards,

Hi, Jared. The exhaust pipes on furnaces and hot water heaters inside your house are usually galvanized, so I don't see why not. Good luck.

Regards,

A. Hi, Tessa. 'Poisoned' is a very strong word. Paracelsus tell us that only the dose makes a poison. I would not worry about it in the least :-)

I think the operative thing to learn is that things that are not intended for food service should not be used for food service. Because then we build no public history; no researcher can say "Wait! I see a pattern here" if people are using such materials privately with no feedback. See if a store has a stainless steel or nickel plated rack that might serve.

Regards,

Thanks Ted, I feel much better! I will throw out my brilliant invention and see if I can find a stainless steel one to replace it!

A. Hi, Eric. You are nowhere near hitting the vaporization point of zinc, so I don't think there will be any zinc in the steam. But stainless hardware is readily available and sounds easier than trying to justify yourself:-)

Regards,

Hi. Many thanks for your advice. Yes, I guess I was just being cheap since stainless hardware is so much more expensive.... But I think I'll just do the right thing, as you suggest, so I don't have to wonder every time I bite into a piece of homemade toast...!

A. Hi Adrian. Sorry but you've lost 'plausible deniability' and you can't do what you were planning. California's zero tolerance for risk but zero information labeling has economic consequences extending far beyond its borders.

You could try aluminum craft wire and hope that California hasn't put their labels on it yet :-)

Regards,