Copper in Cutlery

H

Hathenbruck

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Dec 30, 2018
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OK...I really need to get to the bottom of this. If there's already a thread on this topic, could someone link it?

Anyway, copper in kitchen blades...Is it really going to poison people? I can't seem to find any definitive answers one way or the other. There seem to be a lot of opinions, but no empirical data to back up the claims. I understand what copper toxicity is, but I can't imagine you'd get enough copper transferring to your acidic foods through a sliver of copper touching it for a fraction of a second.

I was berated by a well known knife maker at Bladeshow for having copper in a yanagiba. He basically told me that the copper in that blade was going to poison people, but at the same time he told me Tommie Copper socks and underwear would do that same thing. Now, I respect him as a knife maker, but I don't respect him as a chemist...with zero data to back up his claims. I mean, I've lived most of my life drinking water from copper pipes and drinking alcohol that was distilled in copper, and no copper toxicity yet. Not to mention that copper is a necessary mineral for basically human function.

Does anyone have anything other than an opinion on this matter? I'd surely appreciate it.
 
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Copper is toxic when ingested. Copperware looks nice, but is high maintenance. Improper care and use makes it risky.

IOW, don't eat pennies!
 
I've used a copper sugar pot in the kitchen for years

Bowls designed to whip egg whites in are copper; the trace copper helps to stabilite the egg whites

Traditional jam cooking vessels are copper

As long as the copper is kept tarnish free it's perfectly safe
 
Chefget said:
I've used a copper sugar pot in the kitchen for years

Bowls designed to whip egg whites in are copper; the trace copper helps to stabilite the egg whites

Traditional jam cooking vessels are copper

As long as the copper is kept tarnish free it's perfectly safe
Click to expand...
Now this makes sense to me.
 
Copper is supposedly quite a risk if you cut yourself with it. food utensils etc pose very little risk......unless you cut yourself on the edge of the bowl.
This is purely anecdotal.. Plumbers should know the dangers of copper cuts, although many are now using plastic quick fits.
 
The best article I’ve found is on Pub Med. they ran tests with copper foil with four different acids. Tests were based on heat and time. The tests with low temps and short times, a few minutes, yielded extremely low transfer. The tests under higher temps and, I think the time was 3 hours, yielded more significant transfer.

To me, this says the swipe of a blade through some acidic food will do absolutely nothing as far as copper transfer into the food, but still isn’t the exact data I’m looking for.
 
Copper is really low on the toxicity scale. You'd probably have to eat the knife to be poisoned by it.
A lot of people wear jewelry that contains copper, including some gold alloys. You never hear any complaints about copper poisoning from jewelry.
Pennies are copper, has anybody ever been poisoned by handling money?
BTW, copper has very good anti-bacterial properties, so having copper in the blade isn't all bad....
 
Ingesting copper is the concern, not touching it. Acids from foods and how they impact copper is something to consider.

Also, natural oils on the skin offer some protection.
 
I remember copper bracelets being all the rage at one time, supposedly offering a measure of protection against arthritis and rheumatism, I even bought a solid copper watch From a SA copper mine. Lots of people walked round with green wrists. A cut from copper can be serious, not the cut as such but the copper direct to wound.
 

Copper poisoning​



Copper can be poisonous if it is swallowed or inhaled.


Where Found​



Copper is found in these products:
  • Certain coins - all pennies in the United States made before 1982 contain copper
  • Certain insecticides and fungicides
  • Copper wire
  • Some aquarium products
  • Vitamin and mineral supplements (copper is an essential micronutrient, but too much can be toxic)
Other products may also contain copper.


Symptoms​



Swallowing large amounts of copper may cause:
  • Abdominal pain
  • Diarrhea
  • Vomiting
  • Yellow skin and whites of the eyes (jaundice)
Touching large amounts of copper can cause the hair to turn a different color (green). Breathing in copper dust and fumes may cause an acute syndrome of metal fume fever (MFF). People with MFF have:
  • Chest pain
  • Chills
  • Cough
  • Fever
  • General weakness
  • Headache
  • Metallic taste in the mouth
Long-term exposure may cause lung inflammation and permanent scarring. This can lead to decreased lung function.
Symptoms of long-term exposure include:
  • Anemia (low red blood cell count)
  • Burning sensation
  • Chills
  • Convulsions
  • Dementia
  • Diarrhea (often bloody and may be blue in color)
  • Difficulty speaking
  • Fever
  • Involuntary movements
  • Jaundice (yellow skin)
  • Kidney failure
  • Liver failure
  • Metallic taste in the mouth
  • Muscle aches
  • Nausea
  • Pain
  • Shock
  • Tremor (shaking)
  • Vomiting
  • Weakness
Hey was the initials of the guy that didn't like copper JF?
 
Copper toxicity is a real thing. A friend of mine (former SEAL, then worked for Raytheon in underwater vehicle design) was medically retired from the Navy because of it. BUT, a sliver of copper used in cook ware, pans, pots, knives...ain't going to do it.
 
to paraphrase Dr McCoy: “ Jim … I’m a chemist not a doctor….” I can’t speak to copper toxicity… but as a chemist I can venture that it can’t poison you if it does not get into your system. From the chemistry point of view, copper will be “dissolved” by acidic foods. The plan copper bowls shown above are used with things like egg whites and sugar syrup, neither of which are acidic. Traditional copper cookware used with acidic foods was/is coated on the inside with molten tin (I have several pieces like this). Nowadays it is common for there to be an inside laminated layer of stainless steel.

Edit: oh … and also think about electricians. They handle/touch bare copper all day for years on end. I don’t recall hearing anything about an epidemic of copper poisoning in electricians…

So … as far as copper in knives go, stay away from using on acidic foods … doing so will quickly tarnish the copper anyway.
 
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Danke42 said:

Copper poisoning​



Copper can be poisonous if it is swallowed or inhaled.


Where Found​



Copper is found in these products:
  • Certain coins - all pennies in the United States made before 1982 contain copper
  • Certain insecticides and fungicides
  • Copper wire
  • Some aquarium products
  • Vitamin and mineral supplements (copper is an essential micronutrient, but too much can be toxic)
Other products may also contain copper.


Symptoms​



Swallowing large amounts of copper may cause:
  • Abdominal pain
  • Diarrhea
  • Vomiting
  • Yellow skin and whites of the eyes (jaundice)
Touching large amounts of copper can cause the hair to turn a different color (green). Breathing in copper dust and fumes may cause an acute syndrome of metal fume fever (MFF). People with MFF have:
  • Chest pain
  • Chills
  • Cough
  • Fever
  • General weakness
  • Headache
  • Metallic taste in the mouth
Long-term exposure may cause lung inflammation and permanent scarring. This can lead to decreased lung function.
Symptoms of long-term exposure include:
  • Anemia (low red blood cell count)
  • Burning sensation
  • Chills
  • Convulsions
  • Dementia
  • Diarrhea (often bloody and may be blue in color)
  • Difficulty speaking
  • Fever
  • Involuntary movements
  • Jaundice (yellow skin)
  • Kidney failure
  • Liver failure
  • Metallic taste in the mouth
  • Muscle aches
  • Nausea
  • Pain
  • Shock
  • Tremor (shaking)
  • Vomiting
  • Weakness
Hey was the initials of the guy that didn't like copper JF?
Click to expand...
Initials are SS 😁
 
navman said:
Copper toxicity is a real thing. A friend of mine (former SEAL, then worked for Raytheon in underwater vehicle design) was medically retired from the Navy because of it. BUT, a sliver of copper used in cook ware, pans, pots, knives...ain't going to do it.
Click to expand...
This is exactly my thought on it.
 
Cushing H. said:
to paraphrase Dr McCoy: “ Jim … I’m a chemist not a doctor….” I can’t speak to copper toxicity… but as a chemist I can venture that it can’t poison you if it does not get into your system. From the chemistry point of view, copper will be “dissolved” by acidic foods. The plan copper bowls shown above are used with things like egg whites and sugar syrup, neither of which are acidic. Traditional copper cookware used with acidic foods was/is coated on the inside with molten tin (I have several pieces like this). Nowadays it is common for there to be an inside laminated layer of stainless steel.

Edit: oh … and also think about electricians. They handle/touch bare copper all day for years on end. I don’t recall hearing anything about an epidemic of copper poisoning in electricians…

So … as far as copper in knives go, stay away from using on acidic foods … doing so will quickly tarnish the copper anyway.
Click to expand...
I appreciate this. Very good points.
 
Never heard of this.....
The best water lines are copper.
The best confectioners bowls are copper.
It's used in food processing plants/brewers Alot.
It's added to our multi vitamins.

Not saying that it isn't true. I'm sure copper toxicity is a thing...... But I Guaranty more people die from consuming water each year.
 
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