Copper Heating Element Safety in Water Urn
January 13, 2021 5:31 AM   Subscribe

So I have a huge water heating urn dispenser with one copper heating element and 2 which seem to be stainless. I have a question about whether the copper one is safe or toxic. I keep hearing mixed reports about copper being toxic and it can accumulate in the body. Can someone please cite research of its safety or alternately of its toxicity? The urn isn't being used for this reason. Would like to settle this once and for all? TIA
posted by watercarrier to Food & Drink (14 answers total)
 
Copper is widely used for plumbing, including in new construction. If you have a hot water heater in your house, go look and see if the supply/exit lines are copper. Admittedly, toxic materials have been used for plumbing in the past, but from what I can tell the only reason they don't use copper for everything today is that it's expensive.
posted by Huffy Puffy at 5:55 AM on January 13 [1 favorite]


Again not a research study, but here in India people drink out of copper cups / mugs /water bottles all the time. As I understand, it's seen also as a way to get some trace copper and therefore beneficial.
posted by athirstforsalt at 5:57 AM on January 13


EDIT: I want to clarify that this heating urn is to heat water for hot drinks. Not for plumbing. Thanks
posted by watercarrier at 5:57 AM on January 13


From the Minnesota Department of Health:

Drinking water with more than 1,300 micrograms of copper per liter of water (µg/L)* can be a health risk for everyone. Infants and people with Wilson’s disease may need water with an even lower level of copper to stay safe.

I wouldn't personally use a copper coil to heat water to boiling. The leaching effect will be minimal with cold pipes and the protective layer of oxide. When heated to boiling, there will be continuous dissolving of these protective compounds, allowing for copper to go into solution. You could easily hit the toxic threshold with ingestion of water heated this way.
posted by sydnius at 6:18 AM on January 13 [1 favorite]


From Wikipedia, re: copper toxicity and copper use in cookware - emphasis mine:
Acute exposure and attendant copper toxicity is possible when cooking or storing highly acidic foods in unlined copper vessels for extended periods, or by exposing foodstuffs to reactive copper salts (copper corrosion, or verdigris). Continuous, small ("chronic") exposures of acidic foods to copper may also result in toxicity in cases where either surface area interaction potentials are significant, pH is exceptionally low and concentrated (in the case of cooking with, for example, vinegar or wine), or both, and insufficient time elapses between exposures for normal homeostatic elimination of excess copper.
If you're only heating water and not, say vinegar in this tea urn, I don't think there's an issue.
posted by EndsOfInvention at 6:20 AM on January 13 [3 favorites]


huge water heating urn dispenser
...
to clarify that this heating urn is to heat water for hot drinks

Do you mean it was designed to heat water for drinks, or just that you are intending to used it to heat water for drinks?

To me "urn" means people will drink from it, and I'd investigate the certifications of the device - but if you ask this q then I suppose you're from the US, and can't necessarily trust certifications on the device.
posted by pompomtom at 6:24 AM on January 13


That all aside: you'll be fine. Look up the etymology of "plumbing".
posted by pompomtom at 6:28 AM on January 13


Additionally, tankless water heaters use copper heating elements since copper conducts heat very well. If copper toxicity from heating water was an issue, then it would be showing up hugely amongst populations who make heavy use of tankless heaters for their hot water.
posted by EndsOfInvention at 6:31 AM on January 13 [2 favorites]


@ pompomtom it's a heating urn for hot drinks. Like this
posted by watercarrier at 6:34 AM on January 13


Fine as.
posted by pompomtom at 6:37 AM on January 13


Is it UL/ULC listed? While that's primarily for electrical safety, Underwriters Laboratories exist to ensure products don't cause excessive liabilities for insurers.
posted by scruss at 10:16 AM on January 13 [1 favorite]


If copper toxicity from heating water was an issue, then it would be showing up hugely amongst populations who make heavy use of tankless heaters for their hot water.

Do people commonly drink from their hot tap where you live?

Everywhere I've lived it's a no-no. So no, copper toxicity won't be showing up in those populations who don't drink from their hot water supply.
posted by HiroProtagonist at 8:50 PM on January 13



Everywhere I've lived it's a no-no. So no, copper toxicity won't be showing up in those populations who don't drink from their hot water supply.


Copper toxicity takes many forms and can show up as chronic disease. Which is why I'm a bit alarmed that these water dispensers are being manufactured and sold to unsuspecting consumers.
posted by watercarrier at 10:17 PM on January 13


Here’s what one of the national safety standards says in the USA. Note that if your appliance has a CE logo, it also complies with European food/appliance standards, which likely differ at least a little bit.

NSF (National Sanitary Foundation)/ANSI 51 defines “Food Equipment Materials” for commercial food equipment.

“Copper and copper alloys shall not be used in a food zone or splash zone except where rendered corrosion resistant or where exposure to food is limited to potable, non-carbonated water under constant service pressure. [Exceptions for brass/bronze and copper-nickel alloys]
“Brass and bronze may be used in a food zone or splash zone only where rendered corrosion resistant or where exposure to food is clearly and specifically limited to tea, coffee, or water.” [and there’s a limit on lead content; copper-nickel alloys the same thing, but limited to food/beverages with pH over 6]

Water looks like it’s allowed, barring evidence of corrosion. Other stuff, depends on what it is and what your actual material is. It does seem strange to me that it would be using different materials for different heating elements.
posted by Huffy Puffy at 9:36 AM on January 14 [1 favorite]


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