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Dangers of Heating Zinc for Science Project

Q. I was just wondering that if you get zinc so hot that the temperature reaches 120 degrees Fahrenheit if it would give off some kind of gas that could kill you or anything. I an doing my science project on which kind of metal gets hottest the quickest and I did not want it to get so hot and let off some kind of gas and kill or hurt people in the whole school. So please if there is anyway possible that you could give me a response about zinc as soon as possible.

Thank-You Student At Pendleton County High

Brian G.
- Riverton West Virginia US

A. Hi Brian. Best of luck with your project, and thanks for being careful!

But 120 °F isn't even as hot as some places get in the summer. I just read that outside temperatures of over 130 degrees have been recorded. Your attic probably reaches 120 in the summer. Are you sure you have that temperature right? If you were welding or putting a cutting torch on zinc, I'd worry. Or if you were eating off a zinc-plated sheet I'd worry a bit.


I think your chief concern should be that nobody touches the metals and gets burned, and I'd suggest a warning sign to that effect.

Good luck!

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

A. Kid,

I have personally been quite sick by breathing the gaseous oxide of the metal in question. I was welding galvanized pipe and failed to note the direction of the wind. I was sick for a day.

I doubt that 130 degrees would cause any problem with it. I think that your investigation is in the direction of "specific heat". You will find listings of how much heat energy is required to increase each type of material, by weight, an equal amount.

Norman B. Czerski
- Eagle River, Alaska USA

Q. I am building a fire pit using two half circles basement window wells. They are galvanized steel and my son said that they would give off fumes that are harmful. I agreed with him but feel that a good fire would drive out the zinc. Is this true?

John Carroll
Designer - Marlton, New Jersey
September 10, 2010

A. Hi, John. As long as this fire pit is outside, which I would certainly expect, I don't think there is much of a problem. While the heart of a hot fire is hot enough to melt the zinc, and maybe to vaporize it, I think you'd find it hard to build a fire that would vaporize the zinc except in a tiny spot, and then only on the inside wall, not the outside wall. Welding is something else, involving way higher temperatures, and inhaling the fumes because you're staying very close to watch your work.

Zinc is not a toxic material but a necessary micro nutrient (cold prevention tablets are actually zinc supplements), and a normal outdoor exposure to the small amount from a camp fires wouldn't worry me personally at all.


Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey
September 11, 2010

thumbs up sign Thanks, I'll be building my fire pit and passing on the design and information.

John Carroll [returning]
- Marlton, New Jersey, USA
September 12, 2010

Q. I am wondering if heating Zinc to 450° F. in a household oven will cause issues? The oven is not vented to the outside.
Also it would be good to know at roughly what temperature Zinc does become toxic if anyone has that information.

Gene Collins
- Seattle, Washington, USA
February 14, 2012

A. Hello Gene.

Zinc is not a toxin, it is an essential nutrient. But a gross overdose can be a nasty problem.

Zinc doesn't become "toxic" at any temperature, but what does happen at the vaporization temperature of zinc (about 1600 ° F) is that the metal turns to a gas, such that it can be easy to inhale an overdose if you are a welder.

An oven in the kitchen is for cooking food, and that's all it should be used for! It's not a question of what facets of which hobbies and science experiments and household repairs you can safely use your kitchen oven for :-)

Apologies if that sounds harsh, but the point is that if things are used for purposes for which they weren't intended, it simply isn't possible to acquire the necessary history, data, and experience for anyone to say what is safe and what isn't. For example, what do you mean by "heating zinc to 450 °F" -- it's probably something very different from the next guy. 100% pure zinc might be no problem, but leaded zinc might; solid Zinc sheet for countertops, etc. [affil link] might not be a problem but putting galvanized metal with a hexavalent chrome conversion coating into a heated kitchen oven might be crazy.

Please try to post the exact details of your question rather than casting it in the abstract. Thanks.


Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey
February 14, 2012

Q. I want to put a sheet of 28 gauge zinc plated steel in the bottom of a barrel grill and I wanted to know whether that will be too much heat from the coals to cause toxic gases.

Joshua Lewis
- Birmingham,Alabama
July 3, 2017

A. Hi Joshua. Using the term 'toxic gases' will make it hard for you to understand the nature of the problem. Zinc is not a 'toxic gas'; it is an essential micronutrient. The problem is that welders heat a lot of zinc to the vaporization point, creating a cloud of zinc oxide, and then inhale it into their lungs, getting a gross overdose. By way of parallel, instead of taking one baby aspirin, they are swallowing the whole bottle.

In a world of non-inspected imported foods from every hovel in the world, listeria, salmonella, rodent droppings, and fecal coliform poisoning are legitimate concerns, but I truly doubt that zinc poisoning from lining your barrel grill is. But get a hot fire going with no food on the grill the first time.


pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha - Pine Beach, New Jersey
July 2017

Is a galvanized clothes dryer drum a health hazard?

Q. I am considering buying a clothes dryer and the drum is made of galvanized steel. Could this pose a health hazard to my family? I'm worried that the heat of the dryer may cause the zinc to off gas or rub off on our clothes. It's the Speed Queen dryer. I already purchased the washer as I loved it but would like to get the matching dryer if it's safe. I have a metal sensitivity so also concerned for that reason, but I react fine to stainless steel.

Catherine Whitfield
- Chattanooga Tennessee USA
January 3, 2018

A. Hi Catherine. I wish there wasn't quite this level of fear about this important micronutrient...

You need water, but if you are submerged in it you'll fill your lungs with it and drown.
You need zinc as well, but if you weld a bunch of it, vaporizing it in the white-hot electric-arc heat and filling the air with clouds of it, you'll fill your lungs with it and probably get "metal fume fever".
A galvanized clothes dryer drum should be of no concern at all.


pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha - Pine Beach, New Jersey
January 2018

Q. Hey guys I am making a forced air 12-volt tent heater. A 2-foot pipe will sit above a flame and be heated to about 550 °F. A metal flexible dryer hose will be attached to each end and the 12 volt fan will blow the heated air into my tent. My question is, what type of 3-inch metal type of pipe can be safely heated where no fumes will be created internally from the heat. The flame will be outside of my tent.

Gary dry
- Riverside California USA
February 15, 2018

A. Hi Gary. You can use either plain black steel (black iron) or stainless steel. I suspect the plain steel will be very affordable and the stainless not so much. But other readers should not take this as a clue unless they know exactly what they are doing because carbon monoxide poisoning is always a concern. Good luck.


pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha - Pine Beach, New Jersey
February 2018

December 1, 2018

The E-X-A-C-T situation:

Baking bread in a cast iron Dutch oven outdoors using charcoal briquets to heat the oven to 350-450 degrees. Instead of using aluminum foil to create a baking rack for air circulation and preventing the bread from burning on the bottom, is it safe to use fifteen pennies in three stacks of five pennies each to create a rack? Would it be better to use pre-1982 pennies, since they have far less zinc than post 1982 pennies?

Thank you!

Jennifer Rader
- Reno, Nevada, USA

A. Hi Jennifer. Sounds like no problem to me.


pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha - Pine Beach, New Jersey
December 2018

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