Summary for galvanized iron fumes Discussion
Galvanized iron fumes are the focus of this thread, and the main concern is what happens when zinc-coated steel is burned or welded. Dan Gro asks how toxic the fumes are, how to identify galvanized metal, and whether the yellow smoke or residue from hardware-store steel is dangerous. Several replies stress that the real hazard is the fumes from welding or torch-cutting galvanized material, not ordinary handling. Matt Cartwright says zinc oxide can cause a quick headache and recommends a respirator. Ted Mooney clarifies that exposure to fumes from burning or welding galvanized steel can cause illness, but vague symptoms should be checked by a doctor rather than guessed at. Ben Fairbank says zinc oxide is not highly toxic but can make you feel very sick, and advises a positive-flow mask. Milk is mentioned as a traditional remedy, but the thread agrees it is not a substitute for proper ventilation, respiratory protection, and medical care if symptoms occur.
Q. I do some blacksmithing, as a hobby, and I just read in a book that galvanized iron fumes are toxic. I am wondering (a) how toxic they are, (b) how to tell what metal is galvanized or not (c) if the fumes/yellow stuff that forms on the top and then comes off as fumes from some of the steel I get at the hardware store are toxic, and if they are, how to deal with that, or what other kind of metal to get.
I would really appreciate a response on this as soon as possible, because I don’t want to get galvanize fume poisoning or something.
Dan Gro
– Burlington, Vermont
2001
A. I was told to never weld galvanized pipe. Zinc oxide is bad and gives you a headache very quickly, so you know to stop welding it. I have also heard that milk is a remedy and cleanser for zinc poisoning. If you must weld galvanized then wear a respirator.
Matt Cartwright
– Portland, Oregon
2001
A. As far as drinking milk after being around Galvanize metal, I couldn’t say! My husband has been up all night sick, he worked with galvanized pipes at work yesterday. He drank a large glass of milk. Didn’t seem to help. Doesn’t your employer have to present you with some kind of warning on this stuff?
Martha [last name deleted for privacy by Editor]
– Georgia
2003
2003
A. Hi Martha. Unfortunately, “worked with” is vague. I was a plumber’s helper in my youth and worked with galvanized pipe every day; my father worked with galvanized pipe almost every working day of his life and never got sick from it once — because he never welded it or burned it with a torch. It is exposure to the fumes from those operations that causes this illness. Your husband could have fume fever if he was welding, but he also could have food poisoning or the flu or a lot of other things; seeing a doctor is better than guessing :-)
Get back to us with what your husband does. Thanks.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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Q. What if the Galvanized pipe is subjected to radiant heat- about 700°? Will it then give off the same toxic fumes as cutting on it with a torch?
Matt Brubaker
– Arnold, California
2003
A. Hi. Centigrade or Fahrenheit, Matt? If Fahrenheit, it probably isn’t a problem; look up the vaporization temperature of zinc. The other thing is that zinc is not a toxin, it’s an essential micronutrient and is deliberately added to vitamins, cold easing tablets, etc. — so it’s an issue of too much exposure, not any exposure. Welders without proper protective equipment can inhale clouds of it and easily become sick from overexposure.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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June 2015
! I do have first hand experience of galvanic fumes. The zinc almost killed me. The job “had to be done” that day and I was pressured to cut an 8 foot diameter corrugated drain pipe from the inside with oxy-acetylene. 5 hrs after the job I started shaking violently. I was able to literally stumble into a 7-11 and get a 1/2 gallon of milk thankfully remembering years earlier in a safety training. I felt like I had the WORST flu ever but no vomiting. With 20 minutes of drinking this whole half gallon I recovered. I am sure I would have died. Be careful out there. Wear a respirator! BTW this was years ago 20+.
James Henderson
– brentwood, California
May 21, 2009
A. Actually, zinc oxide, which is emitted when you burn or weld galvanizing, is not toxic, however, it will make you feel like hell for a few days. I just got done cutting a lot of galvanized metal with and oxy/ acetylene torch, and I feel nauseous and my lungs feel like I just chained down a carton of Camel filters, but I know I’m in no danger. The body metabolizes zinc (read your vitamins’ label). Go to OSHA’s website if you don’t believe me. If he is burning galvanizing he should be wearing a positive flow mask.
ben fairbank
self/ contractor – logan, utah usa
January 23, 2010
Q. What if you drink the milk before you start the job, just a thought?
Willie Dykes
– Greenville “N” the Great State of Texas
June 19, 2015
A. Hi Willie. I have nothing against traditional cures, and I’m sure the milk won’t hurt you. But this is 2015 and people should not be welding without proper ventilation and/or protective equipment. As Ben says above, if welding or burning galvanized material, the worker should be wearing a positive flow mask.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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June 2015
A. Milk as a treatment for fume fever is a lie!
It does not help because you are not flushing your lungs with it.
Cheap and easy for your employer… just gives the workers a false sense of safety.
Increasing your level of hydration and time are likely why you felt better.
Scott Wares
– Littleton, Colorado, USA
March 19, 2017
Hi Scott. Thanks for making it clear that you feel that drinking milk is ineffective, and that it’s certainly not a sufficient response to poisoning from metal fumes. But calling something a “lie” is accusing people of deliberately trying to deceive us, and I wouldn’t go that far, especially because clinical studies (https://ajcn.nutrition.org/content/65/6/1803.abstract) have shown that calcium does in fact discourage absorption of zinc.
Again though, medical attention, not milk, is what is required in the event of such poisoning. And prevention, through proper air supply, rather than treatment, is what is really called for.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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Need project assistance? $100/hr.
March 2017