I know someone who wants to serve lemonade from a galvanized metal bucket (has to do with a party theme). Since the drink will only be in the bucket a short time it won't have time to dissolve much metal but I wondered what it could dissolve besides zinc? Maybe lead or cadmium?? Thanks.
Eng-Tips is the largest engineering community on the Internet
Intelligent Work Forums for Engineering Professionals
-
Congratulations waross on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!
Does zinc galvanizing contain other heavy metals?
- Thread starter sciguyjim
- Start date
The zinc galvanized coating is comprised of 4 layers. The first three are a combination for zinc and iron the top or outer layer (ETA layer) is ~100% pure zinc. The outermost (Eta) layer of the coating is formed as a covering of pure zinc that is carried out on the material as it is withdrawn from the molten zinc bath. The underlying series of zinc/iron alloys in the coating are the result of a metallurgical reaction between molten zinc and the steel or iron material being galvanized. As the zinc/iron alloys form, they will grow perpendicularly to the steel surface.
The control hot dip specifications are:
ASTM A-153 Zinc Coating (Hot Dip) on Iron and Steel Hardware
A-123 Zinc (Hot Galvanized) Coatings on Iron and Steel Products.
Electroplating specs are
ASTM-B-633:
Type I, II, and III
QQP-416, Revision F:
Type I and II
Class 1,2 and 3
MIL-STD-171-D
The zinc is a heavy metal that reacts with acids. Lemon is a weak citrus acid. So....
The control hot dip specifications are:
ASTM A-153 Zinc Coating (Hot Dip) on Iron and Steel Hardware
A-123 Zinc (Hot Galvanized) Coatings on Iron and Steel Products.
Electroplating specs are
ASTM-B-633:
Type I, II, and III
QQP-416, Revision F:
Type I and II
Class 1,2 and 3
MIL-STD-171-D
The zinc is a heavy metal that reacts with acids. Lemon is a weak citrus acid. So....
- Thread starter
- #3
Since no one authoritatively answered this, I will add my comments. Zinc galvanizing can have chromium in it, and the hexavalent form is a carcinogen. Cr6+ is now grouped with Hg, Pb, and Cd as a restricted substance for use in certain industries, especially automobiles.
The leading trace element (>0.005%) found with zinc are Cadmium and Mercury. Additionally there is Lead and Arsenic. But what is more important is Zinc toxicity. This has been seen in both acute and chronic forms. Intakes of 150 to 450 mg of zinc per day have been associated with low copper status, altered iron function, reduced immune function, and reduced levels of high-density lipoproteins. So why risk it?
Zinc story.
The sewer department wanted us to test our discharge for metals. There wasn’t much discharge so they wanted us to collect it for a week. We got a plastic 55-gallon drum to collect it.
We collected it and the zinc was horribly high. The level was much greater than would be accounted for by the process or by evaporation of the tap water we were using. We had the water tested and consulted experts.
What had happened is that the employee was told to cut the top off the plastic barrel and dump the waste in it. Instead he went to the hardware store and bought a lovely cold process zinc coated funnel.
As other have stated, there are different ways to galvanize. I can tell you one method means a small amount of liquid can leach out a large amount of zinc just by being poured over it once.
We have a washtub we use for parties. We fill it with ice and put bottles in it. (We also put a washboard in it. Amazing the number of people who have never seen one and don’t believe the explanation.) Also, you might try a restaurant supply store. They ought to have a container you can use as a liner.
Tom
The sewer department wanted us to test our discharge for metals. There wasn’t much discharge so they wanted us to collect it for a week. We got a plastic 55-gallon drum to collect it.
We collected it and the zinc was horribly high. The level was much greater than would be accounted for by the process or by evaporation of the tap water we were using. We had the water tested and consulted experts.
What had happened is that the employee was told to cut the top off the plastic barrel and dump the waste in it. Instead he went to the hardware store and bought a lovely cold process zinc coated funnel.
As other have stated, there are different ways to galvanize. I can tell you one method means a small amount of liquid can leach out a large amount of zinc just by being poured over it once.
We have a washtub we use for parties. We fill it with ice and put bottles in it. (We also put a washboard in it. Amazing the number of people who have never seen one and don’t believe the explanation.) Also, you might try a restaurant supply store. They ought to have a container you can use as a liner.
Tom
- Thread starter
- #7
Just got up and dug out my my zinc cold lozenges. The label says they contain 14 mg of "Elemental Zinc" (Zinc Acetate) each, and says adults should not exceed 12 lozenges per day:
12 x 14 = 168mg / day
and should not be taken more than 7 days in a row...
Hmmm...
12 x 14 = 168mg / day
and should not be taken more than 7 days in a row...
Hmmm...
- Thread starter
- #9
Kenneth, I checked the zinc supplement tablets I take and they are 100mg. To get help for viral attacks I'd take about 3 tablets, but only for 1-2 days. Never had any problems. I do have copper supplements because I know about the zinc-copper interaction.
Sorry,
Maybe I should have made it clearer. This was elemental zinc and the health dept, measures in ppm. PPM for something that concentrates in the body can be significant. About half of what is essential in my morning vitamin pill is illegal if I expose my employees to it.
I got a certificate in environmental management, In our law class one of the attorneys said “It doesn’t have to make sense, It’s the law”
Tom
Maybe I should have made it clearer. This was elemental zinc and the health dept, measures in ppm. PPM for something that concentrates in the body can be significant. About half of what is essential in my morning vitamin pill is illegal if I expose my employees to it.
I got a certificate in environmental management, In our law class one of the attorneys said “It doesn’t have to make sense, It’s the law”
Tom
Nothing to be sorry about Tom. You were clear (to me at least). I was really responding to boo1's information:
"Intakes of 150 to 450 mg of zinc per day have been associated with low copper status, altered iron function, reduced immune function, and reduced levels of high-density lipoproteins. So why risk it?"
and not your post (which was very informative, and I thoughly enjoyed reading, by the way).
And I really like your: "About half of what is essential in my morning vitamin pill is illegal if I expose my employees to it."![[smile]](/data/assets/smilies/smile.gif "[smile] [smile]")
"Intakes of 150 to 450 mg of zinc per day have been associated with low copper status, altered iron function, reduced immune function, and reduced levels of high-density lipoproteins. So why risk it?"
and not your post (which was very informative, and I thoughly enjoyed reading, by the way).
And I really like your: "About half of what is essential in my morning vitamin pill is illegal if I expose my employees to it."
Isn't this forum fun.
It goes back to: "a little of a good this is great, too much is .." The data in zinc toxity comes from the USDA.
The envirmental risk assessments we now conduct, are lowering and lowering the exposure limits of heavy metal employees are allowed too have. Sorry if I'm offbase, maybe it is all the mercury I played with as a kid (out thermometers now outlawed).
It goes back to: "a little of a good this is great, too much is .." The data in zinc toxity comes from the USDA.
The envirmental risk assessments we now conduct, are lowering and lowering the exposure limits of heavy metal employees are allowed too have. Sorry if I'm offbase, maybe it is all the mercury I played with as a kid (out thermometers now outlawed).
Oh great, now I end up saying I'm sorry. It wasn't my intention to imply that you were offbase, boo1. I wasn't questioning your information, and didn't think it was taken off the top-of-your-head.
I just thought it was interesting that FDA had apparently apporved a (temporary) dosage level that was in excess of what the USDA has indentified as potentially harmful (for extnded periods?). The closeness of the maximum dosage to the USDA numbers would appear to imply that there potentially some connection. Maybe we really should "read and follow label directions" after all.
As we learn all the things that are harmful to us, I never ceased to be amazed that I've lived as long as I have. I fully expect to drop dead tomorrow, but I'm not going to go too far out of my way to to prove the doomsayers wrong by deliberately (over)exposing myself.
All things in moderation...
I just thought it was interesting that FDA had apparently apporved a (temporary) dosage level that was in excess of what the USDA has indentified as potentially harmful (for extnded periods?). The closeness of the maximum dosage to the USDA numbers would appear to imply that there potentially some connection. Maybe we really should "read and follow label directions" after all.
As we learn all the things that are harmful to us, I never ceased to be amazed that I've lived as long as I have. I fully expect to drop dead tomorrow, but I'm not going to go too far out of my way to to prove the doomsayers wrong by deliberately (over)exposing myself.
All things in moderation...
Well Chaps, Hello, Greetings from the European side of the
pond. over here, it is considered normal to add up to 5%
aluminium to our Hot Dip Zinc Galvanising bath.
So....'Alzheimers Anyone ??' What with all the 'E numbers'
preservatives, anti-oxidants, artificial colourants, sweeteners, and artificial flavourings, and possibly Genetically Modified Lemons used to make the 'lemonade' I
personally wouldnt worry too much about what the drink will pick up from the bucket, its the buckets ability to withstand the chemical cocktail effects I would concern myself with researching...! ;-P)
Regards, (With Tongue FIRMLY PLANTED in my Cheek)
Rembrandt.
pond. over here, it is considered normal to add up to 5%
aluminium to our Hot Dip Zinc Galvanising bath.
So....'Alzheimers Anyone ??' What with all the 'E numbers'
preservatives, anti-oxidants, artificial colourants, sweeteners, and artificial flavourings, and possibly Genetically Modified Lemons used to make the 'lemonade' I
personally wouldnt worry too much about what the drink will pick up from the bucket, its the buckets ability to withstand the chemical cocktail effects I would concern myself with researching...! ;-P)
Regards, (With Tongue FIRMLY PLANTED in my Cheek)
Rembrandt.
As a very wise woman, who looked a lot like my teenage daughter, once said "If you don't understand it pretend it is a compliment and if you think it is an insult just ignore it the first three times." Amazing how well this works and how often it is true.
Tom
Tom
- Thread starter
- #16
Boo, you said "It goes back to: 'a little of a good this is great, too much is ..'"
This reminded me of some examples I use when explaining to people that too much of anything can be bad. For example, we know we need oxygen, but if you breath too much pure oxygen it becomes poisonous. It's possible to drink too much water too.
Things have to be in the right forms too. For this example, think of salt, made of sodium metal and chlorine gas. If you breathed chlorine you'd corrode your lungs and could die. If you somehow managed to swallow a piece of sodium metal, your stomach could literally explode in flames. Both these are obvious poisons, but once they touch each other, there's a flash of heat and fire and presto we have ordinary table salt, which we DO need in our diets.
This reminded me of some examples I use when explaining to people that too much of anything can be bad. For example, we know we need oxygen, but if you breath too much pure oxygen it becomes poisonous. It's possible to drink too much water too.
Things have to be in the right forms too. For this example, think of salt, made of sodium metal and chlorine gas. If you breathed chlorine you'd corrode your lungs and could die. If you somehow managed to swallow a piece of sodium metal, your stomach could literally explode in flames. Both these are obvious poisons, but once they touch each other, there's a flash of heat and fire and presto we have ordinary table salt, which we DO need in our diets.
"Zinc poisoning is mostly accidental from ...., or drinking of acidic juices or brews made in galvanized iron utensils."
After all the info already given I thought I may add something to the original question. Typically the type of container you are talking about would be made from cold rolled steel coil that has been hot dipped in a continous hot dip galv line. The type of product you are talking about would typically have a rather large crystal pattern called a spangle on the surface. This type of galv is normally associate with small amounts of lead and antimony in the zinc( typically << 1%. There may also be other types of contaminants, depending on the location of the original zinc mine. Typically though the zinc would be at least 99% pure. How much of these would be disolved in acidic drink??? I tend to agree with our european friend that all the other things in the lemonade would probably be much worse for you.
Ant
Ant
- Status
Similar threads
