Is Cu(OH)2 Dangerous? | Kitchen Experimentation

[dRic2]

Hi, I was just experimenting in my kitchen and here's what I came up with:

Put some coins (euros) in a glass.
Add some water
Add some $NaHCO_3$
Slowly heat the whole thing.

Since euros' coins are covered with copper I should get a Little bit of $CuCO_3$ and $Cu(OH)_2$ (1:1) and water should turn a Little Green. While the water is boiling some $Cu(OH)_2$ can leave the glass as vapor? Is This dangerous?

 

[Martin0001]

Cu(OH)2 is not volatile and not dangerous.
Few grams consumed would make you sick.

Heating copper oor its alloys with NaHCO3 in water will not produce it anyway.

 

[dRic2]

Thanks

Heating copper oor its alloys with NaHCO3 in water will not produce it anyway

Well I did It a month ago without heating the water and After a while (when all' the water was gone) I found this Green stuff on my Coin. I don't know What It is so After some Quick researches I came up with this idea to test It.

Anyway my "potion" did become a Little Green but maybe it's Just some dirt on the coins

 

[Martin0001]

In presence of air and carbonates some basic carbonates like Cu2(OH)2CO3 can be formed. Exact composition can vary, depending on exact conditions of experiment.
Air presence is critical for that.
These are not dangerous compounds.
Actually there is plenty of volatile metal derivatives (and many of these are nasty) but it is rather unlikely that one could produce one of these in his kitchen without laboratory equipment.
The easiest to make would be perhaps chromyl chloride (CrO2Cl2) produced by reaction of chromates or chromic anhydride with concentrated hydrochloric acid.
This compound is toxic and also strong oxidizer.
Another one would be manganese heptoxide (Mn2O7) produced easily from permanganates and conc. sulfuric acid.
This one is explosive and very powerful oxidizer.

 

[dRic2]

Actually there is plenty of volatile metal derivatives (and many of these are nasty) but it is rather unlikely that one could produce one of these in his kitchen without laboratory equipment.
The easiest to make would be...

Wow that sounds scary, but I don't get how HCl o H2SO4 can be in my kitchen to start the reactions you mentioned.

If you are a Little interetsed (even if i doubt :-D) I can post a picture of the final result... A very strange light blue came up this time.

 

[jim mcnamara]

Copper salts (what you want to make) range in color from green to blue. Some of the compounds mentioned were not in reference to a kitchen, just a mention about some metals. Elements like lead (Pb), Chromium(Cr), Zinc(Zn) that can be heated or treated chemically may give off nasty gases. For example, trained professional welders will not knowing try to weld galvanized metal (Zinc coated). The zinc vapors will damage lung tissue if inhaled. Prolonged exposure is not safe. No amount of lead is considered safe.

Metal fume fever is an industrial disease caused by inhaling welding fume. Perhaps the most common or most well known cause of metal fume fever is welding zinc coated articles (zinc plating, galvanized, zinc spray etc.). The acute symptoms of metal fume fever are usually similar to flu or other lung related discomfort.

from: metalfinishingsltd.co.uk/articles/welding-zinc-coatings/

This says copper II hydroxide is very bad for your eyes, for example. This is why people always wear eye protection in
labs. If you are playing chemist please consider eye safety.

Copper in tiny amounts is required in your diet (Bound up chemically not the pure metal.) Like many things found in foods you eat, a whole lot is bad.

There are fact sheet on the toxicity (or not) of most chemicals - they are usually available as an MSDS sheet. Copper hydroxide:
https://www.nwmissouri.edu/naturalsciences/sds/c/Copper II hydroxide.pdf

Please wear eye protection if you are going to play with copper compounds.

 

[Martin0001]

Copper salts (what you want to make) range in color from green to blue. Some of the compounds mentioned were not in reference to a kitchen, just a mention about some metals. Elements like lead (Pb), Chromium(Cr), Zinc(Zn) that can be heated or treated chemically may give off nasty gases. For example, trained professional welders will not knowing try to weld galvanized metal (Zinc coated). The zinc vapors will damage lung tissue if inhaled. Prolonged exposure is not safe. No amount of lead is considered safe.

from: metalfinishingsltd.co.uk/articles/welding-zinc-coatings/

This says copper II hydroxide is very bad for your eyes, for example. This is why people always wear eye protection in
labs. If you are playing chemist please consider eye safety.

Copper in tiny amounts is required in your diet (Bound up chemically not the pure metal.) Like many things found in foods you eat, a whole lot is bad.

There are fact sheet on the toxicity (or not) of most chemicals - they are usually available as an MSDS sheet. Copper hydroxide:
https://www.nwmissouri.edu/naturalsciences/sds/c/Copper II hydroxide.pdf

Please wear eye protection if you are going to play with copper compounds.

Any chemical other than water or 0.8% solution of salt in your eye is not a good idea but I do not consider copper hydroxide to be particularly dangeros.
For example sodium hydroxide used in households to clean stuffed up sewage pipes is many orders of magnitude more dangerous.
Actually Cu(OH)2 is on of the least dangerous chemicals one can meet in the lab.
MSDS on the other hand are rather legal documents of little utility in real life.
Their primary use is to address corporate legal liability and not to provide sound advice for the staff.
They are subject of countless jokes between lab staff because if taken seriously they would imply that anyone working in the lab should be dead thousand times around or at least develop 50 different cancers.
Problem with MSDS is such that for a novice they are making nearly anything looking very dangerous.
Everyting looks very toxic, extremely corrosive, extremely flammable, cancer causing etc.
The result is that after some time such a person realizes that it is all bs and then treats all chemicals with equal disregard.
Then accidents happen.

Welders will hate dealing with zinc coated pipes but foundry men have no choice. They have to smelt brass on daily basis and metal fume fewer is a constant risk.

 

[jim mcnamara]

@Martin0001 - the MSDS sheets are not bs. Period. They are governmental, sure. And yes brass foundry workers are exposed to metal fumes. Try reading the Copper II hydroxide MSDS sheet. Argue with them. Do you have scientific citations or medical experience to back up your claim? Please do not spout ad hoc guesses on procedures involving safety.

Thanks.

 

[Martin0001]

@Martin0001 - the MSDS sheets are not bs. Period. They are governmental, sure. And yes brass foundry workers are exposed to metal fumes. Try reading the Copper II hydroxide MSDS sheet. Argue with them. Do you have scientific citations or medical experience to back up your claim? Please do not spout ad hoc guesses on procedures involving safety.

Thanks.

Copper hydroxide is a naturally occurring product of corrosion of copper in sea water.
http://www.tandfonline.com/doi/abs/...scroll=top&needAccess=true&journalCode=ysic20
So it can be found on various brass items commonly used in marine industry.
It has no properties which would warrant any extensive handling precautions - to the contrary such corroded items are handled without any care at all and no one is hurt.
Mixture of hydroxide and carbonate can also be found on naturally coroded brass items - again these objects are handled by many on daily basis without any care at all.
Brass and copper parts are not barred from use with drinking water either, very much like copper tubing isnt. They are actualy one of best materials for it.
I will not go and argue with authors of particular MSDS as I have much more interesting things to do but I reassert again that most of these documents are made for legal purpose only and they are plainly speaking nonsense.
As an example you have a refernces to sodium chloride (kitchen salt) and 10% acetic acid (kitchen viniger) below:
http://www.sciencelab.com/msds.php?msdsId=9927593
http://www.sciencelab.com/msds.php?msdsId=9925519
You will for example find under 10% acetic acid "never add water to this product" between other nonsense.

You should perhaps better investigate properties of particular chemicals before pursuing "everything is very dangerous" agenda.
Such approach is a plain misinformation and yes, it does lead to accidents for reasons which I have already explained.

 

[fresh_42]

the MSDS sheets are not bs. Period.

This is indeed important, especially if we advise kids or readers who are not familiar in handling chemicals of any kind. To underestimate potential dangers might be o.k. for an experienced chemical engineer but never for beginners. I like to explicitly praise the OP to ask instead of relying to unqualified sources or risk anything. It's less about a specific chemical here, as the general attitude toward chemicals in general and recommendations on the internet, where many inexperienced kids might read it. It is simply a matter of responsibility, especially when combining different chemicals with unknown (to the experimenter) outcome.

You should perhaps better investigate properties of particular chemicals before pursuing "everything is very dangerous" agenda.

I do not know a single instance, in which an argument like "but this or that is worse" could be applied to draw any conclusion.

Again, being cautious is important, even for seemingly harmless chemicals, if not even especially with them. @dRic2 did the right thing to ask beforehand. Underestimation is the source for most accidents in life. And the MSDS sheets exist for good reason.

Thread closed.