Cheers Steve. I'll have a gander!
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Cheers Steve. I'll have a gander!
Hi there, I am a smallholder in West Wales who has been keen to try cold smoking for some time. Have built a hanging chamber in an old galvanised metal dustbin and am looking to do my first burn this weekend. Have cured a loin of pork and purchased the little Pro Q cold smoke generator so fingers crossed!
It looks like it would have to be very, very hot smoking for zinc to give off fumes. According to the following web page - around 900º C
"When zinc is raised to a high temperature (at or above its boiling point around 900C), it burns and forms zinc oxide smoke. Like any kind of smoke, zinc oxide will irritate the lungs, leading to difficulty breathing: This is not a dangerous situation and it clears up immediately when you move away from the source of the fumes. People exposed to high concentrations of zinc oxide over a prolonged period of time can also develop a condition known as the "zinc chills", "metal fume fever", "brass-founders ague", or a number of other colorful terms. This involves fever, tremors, and other unpleasant symptoms."
Disclaimer - I have no prior knowlege of the subject and cannot verify the validity of this website, so best to do your own research.
BTW I have used a galvanised incinerator bin in the past and saw no evidence of fumes being given off during it's use and you would have thought they would have been banned if they gave off dangerous fumes during normal use.
There is a lot of paranoia about using zinc in smokers/BBQs and it is something that is often quoted on forums as being a dangerous thing to do. When you try to find evidence of any potential danger or any official food safety guidelines it becomes evident that most of what is posted is actually urban myth and usually only re-posts of other peoples posts.
The only official guidelines I have managed to find regarding the use of zinc in is that it should not come in direct contact with the food or be where liquids can splash onto it and then drip back onto the food.
You do need to ensure that the racks that you place the food on are not zinc plated and, especially when cold smoking, ensure that there is no galvanised metal directly above the food where moisture from the smoke could condense and then drip onto the food below.
Hello Wade. Nope! You knew I would see this buddy. I gotta disagree as you know. We have been here before. I agree TOTALLY with your facts. You can find NO evidence, etc.. Then you start the disclaimers: "You do need to ensure that the racks that you place the food on are not zinc plated and, especially when cold smoking, ensure that there is no galvanised metal directly above the food where moisture from the smoke could condense and then drip onto the food below." My response remains the same: IF I have to make sure of x,y,z. IF I shouldn't use it on a Tuesday; WHY would I put it in my smoker AT ALL?? Why take that chance with family and friends?
I'll give you an example of my argument that supports your position; believe it or not: I'll bet you and many other U.K. members would be HORRIFIED to learn that all the while my 2 children were growing up I kept 2 fully loaded guns in my house AT ALL TIMES. OUT IN THE OPEN. 1 was under my mattress. The other hung above our bed. ( BTW; don't mess with my EX. She could shoot you in the eye at 20 meters with a handgun; with a rifle, you weren't safe at 300 meters if she could see you. ) Now I can quote you disclaimers but many of you will NEVER agree that I was doing a right thing. Just to say; there were precautions and those were EXTREMELY tested. Just sayin.
The argument works the same in both our minds; WHY TAKE THE RISK? Just my opinion. NO / ZERO scientific fact. Keep Smokin!
Hi Danny - There are no disclaimers in my post - I am just stating what the official documentation on the subject supports. The only official limitation of the use of zinc is that it should not be used on utensils or surfaces that will come into direct contact with the foods or can drip onto the foods.
If someone can come up with good evidence that using galvanised metal on non food contact surfaces in a smoker is hazardous then I will happily review my position on it, however the fears people express here (and on some other forums) currently appears to be mostly urban myth. You ask "Why take the risk?" and I counter that with "What risk?"
We cannot recommend avoiding the use of something in a smoker just because we cannot find anything that says it IS safe. If so we would ban a lot of things that we currently routinely use today. On the other hand there is evidence out there that the smoke itself is hazardous. A good example of this is in the US National Library of Medicine - Smoked food and cancer https://www.ncbi.nlm.nih.gov/pubmed/7447916. Should we therefore also recommend that people do not use smoke in their smokers? Search in Google and you will find any number of credible sources that warn of the hazards of smoking and curing but there is very little when it comes to the hazards associated with the use of galvanised components in smokers or ovens.
If the use of galvanised material was hazardous enough for us to be that concerned over then you would expect that there would be a lot of official information out there warning us about it. Unfortunately that does not appear to be the case. In fact there is a lot of documentation regarding where it IS used with food
The FDA's own documentation talks about the use of galvanised surfaces in food production and describes the limitations for its use as
"4-101.15 Galvanized Metal, Use Limitation.
Galvanized means iron or steel coated with zinc, a heavy metal that may be leached from galvanized containers into foods that are high in water content. The risk of leaching increases with increased acidity of foods contacting the galvanized container."
In the Association of Food and Drug Officials. 2002. Food Code: Pocket Guide for Regulators, the use of galvanised metal is described as being limited to certain foodstuffs only
"Materials for Construction and Repair – Galvanized Metal (4-101.15)
• Galvanized metal may not be used for utensils or food-contact surfaces or equipment that are used for beverages, moist food, hygroscopic food, and contact with acidic foods."
The American National Standard/NSF International Standard have the following to say about coated metals in their document on "Food Equipment Materials" http://standards.nsf.org/apps/group_public/download.php/3941/nsf51-97.pdf
"4.2 Food zone materials shall not contain lead, arsenic, cadmium, or mercury as intentional ingredients, except where brass and bronze are specifically permitted for use under 7.3.2.
4.3 Coatings containing lead as an intentional ingredient shall not be used on food equipment surfaces, including splash zones and nonfood zones. Coatings with an unintentional lead content (lead impurity) greater than 0.06% shall not be used. Materials shall be corrosion resistant in the intended end use environment. Protective coatings may be used to render a material corrosion resistant, except as prohibited in 7.4, 7.5, and 7.6. Protective coatings shall remain intact under use conditions and shall conform to the applicable requirements in 7.4, 7.5, and 7.6."
They are being very specific here about the hazards associated with a number of metals (including lead) but there is no mention of zinc or galvanisation being one of them. It does however say where zinc coated materials cannot be used - which suggests that in other situations it can be....
"7.4.2 Zinc coated materials. Galvanized materials and other zinc coated materials shall not be used on surfaces intended for direct food contact"
This is what is referred to as the "Food Zone" which is defined as
"3.5 food zone: Equipment surfaces intended to be in direct contact with food and equipment surfaces that food may contact and then drain drip, or splash back into food or onto surfaces that are
intended to be in direct contact with food."
Yes, there are limitations as to where zinc can be used with food, however this is not a basis upon which we should recommend it not to be used when it is used appropriately.
We won't argue my friend. I am in total agreement with you and the scientific evidence you use to back your opinion. You CAN use galvanized metal in a smoker. I said it. I have a good idea. This is the wrong place for this discussion. I'll post a thread on the open forum and then you, I and others can discuss this and offer our explanations and opinions. This has been going on for a long time and I think there should be an agreement as to how we as a Forum should handle this question. Keep Smokin!
Thanks everyone. I am only using the galvanised bid as a cold smoking chamber. The meat was suspended from stainless steel butchers hooks from a stainless steel threaded bar bolted through the top of the bin. The Pro Q smoker was then put in the bottom of the bin and provided smoke for 10hours with no noticeable increase in the ambient temperature of the bin, and no evidence of any condensation. The bacon tasted great but I may try 20 hours next time. The 2nd picture shows the difference in siz and colour of the smoked and unsmoked part of the loin.