I read from WA state dept health https://www.doh.wa.gov/portals/1/Documents/pubs/331-178.pdf that hot water disolves copper more copper than cold water.

Use cold water for drinking and cooking. Because hot water dissolves more copper than cold water, limit consumption of water from the hot water tap.

Is this correct that hot water dissolves copper more than cold?

  • $\begingroup$ Reactions are faster and compounds generally more soluble in hot water, so probably yes. BTW, who would ever consume water from the hot water tap ?? $\endgroup$
    – Poutnik
    Nov 8 '20 at 7:13
  • $\begingroup$ @Poutnik - why would you not use water from the hot water tap? It is cold water heated up, just as you might do in a pan, teapot, or coffee machine. $\endgroup$
    – Jon Custer
    Nov 9 '20 at 18:15
  • $\begingroup$ @JonCuster In a shortcut, if 2 are doing the same, the result is not the same. The result very much depends on the source, distance, pipe state and the way of usage the system. In one extreme, in is like from the kettle. In other extreme, it is something between being a biological ticking bomb of Legionella or various patogenic Protea (like the one wandering along the nasal neuron path to the brain and kills you in 24 hours), or sensoric disaster. $\endgroup$
    – Poutnik
    Nov 9 '20 at 19:00

Actually, the topic of this question involves an important health care issue surrounding exposure to copper sources in varying conditions.

For example, in case of acidic drinking water with copper plumbing, to quote a 1980 article in Archives of Disease in Childhood:

The boy's copper toxicosis was attributed to the ingestion of water which had a high copper concentration. Although the family's well water contained little copper, it had a pH of 3.8-4.8, and dissolved copper from the domestic plumbing. Three explanations may be offered... Thirdly, he had been fed on cows' milk diluted with water, and it is known that the availability for absorption of copper in milk is greater than in other foods.[4]

Generally, applying heat is known to increase the speed of chemical reaction and relatedly, increased copper poisoning is found in cultures employing copperware, especially in combination with common milk consumption, to quote a source:

Indian childhood cirrhosis:
One manifestation of copper toxicity, cirrhosis of the liver in children (Indian childhood cirrhosis), has been linked to boiling milk in copper cookware.

So, caution and education is especially required in environments with potential copper exposure involving acidic conditions, warming and apparently, foods (like milk), noted to promote copper accumulation.


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