Copper carbonate

[nframe]

I have a question for the chemists among you: is it safe to use copper carbonate to colour soap? The powder is a beautiful pale green/turquoise colour and I have read that, in an alkaline environment, it turns turquoise. Obviously, I would only use a very small amount but I worry about its suitability. Last question: would you dilute it in water or oil?

 

[cgpeanut]

Copper Carbonate
Page 1 of 10
SDS Preparation Date (mm/dd/yyyy): 03/21/2013
SAFETY DATA SHEET
SECTION 1. IDENTIFICATION
Product identifier used on the label
Copper Carbonate
:
Product Code(s)
:
None reported.
Not available.
:
Recommended use of the chemical and restrictions on use
Chemical family
:
Metal compounds
Name, address, and telephone number of
the supplier:
Name, address, and telephone number of
the manufacturer:
World Metal, L.L.C.
Refer to supplier
10701
Corporate Drive
Suite 184
Stafford, TX, USA
77477
281
-
491
-
7474
:
Supplier's Telephone #
24 Hr. Emergency Tel #
:
(800) 424
-
9300 (CHEMTREC)
SECTION 2. HAZARDS IDENTIFICATION
Classification of the chemical
Light green powder. Odourless.
Most important hazards This material is classified as hazardous under OSHA regulations (29CFR 1910.1200) (Hazcom 2012).
Hazardous classification:
Acute toxicity
-
Oral
-
Category 4
Skin Irritant
-
Category 2
Eye irritation
-
Category 2A
WHMI
S information: This product is a WHMIS Controlled Product. It meets one or more of the criteria for a controlled product
provided in Part IV of the Canadian Controlled Products Regulations (CPR). WHMIS classification:
Class D2B (Materials Causing Ot
her Toxic Effects, Toxic Material

 

[DeeAnna]

It's good to know the SDS (MSDS), but that information is about the safety and proper handling of the bulk chemical. It doesn't really answer the OP's question about whether it's safe to use in soap.

 

[OldHippie]

"Hazardous classification: Acute toxicity
Category 4 Skin Irritant"
Sounds like a bad idea to me. I don't see where it is used as a colorant anywhere (maybe a firing glaze). Perhaps there's a reason.

 

[NsMar42111]

We used it in pottery and I remember having to wear a mask and gloves to handle it-not something I want to wash with ! I'd stick with micas from reputable suppliers myself

 

[lmosca]

I wouldn't use it for several reasons.

1) Color intensity: the refractive index of basic copper carbonate (you cannot have copper carbonate alone, it is an equimolar mixture of Copper carbonate x copper hydroxide) is quite low, at 1.66, that is, it's a very transparent pigment. For comparison, iron oxides are around 2.5, up there with titanium dioxide. That's why it takes a little of those to make a good color. With copper carbonate (malachite green) you'll have to use a lot.

2) Copper carbonate is unstable in acid and alkaline conditions, in acid will decompose to form the aquo-ion (a very pale blue) [Cu(H2O)n]2+, in strongly alkaline solutions it will dissolve to form hydroxocuprates [Cu(OH)4-n(X)n]2-, which are a deep blue. That is the color will morph over time, and will not be reliable.

3) Copper ions might be catalytic for fatty acid oxidation, that is you will literally promote rancidity of the oil, soap and formation of DOS. Scrap the might, they are for sure, as they are used for reactions on double and triple bonds in chemistry.

4) Toxicity issue, even if it's a rinse off product. Not only, copper compounds are extremely toxic for aquatic life, though the doses you will drain in the sewage are not even comparable to what we discharge from industries. Though, it's not an excuse to do it

 

[lmosca]

I forgot to add that basic copper carbonate pigments come in two varieties, green verditer and blue verditer. To get a nice turquoise shade you will have to mix them together.
I believe that a good turquoise mica will be far less expensive than quality inorganic pigments for oil painting (which are, nowadays, a rarity to find).
Alternatively, chrome green pigment and blue ultramarine might be combined to get the turquoise shade you want (and lightened with TD, if needed). They are both very intense pigments!

 

[DeeAnna]

I hadn't thought about the issue of copper catalyzing fatty-acid oxidation in regards to this particular thread. Good point!

Yes, that's a definite for-sure problem, and you don't want that in your soap.

 

[nframe]

Thank you all for this. I guess that I will not use it then. I have plenty of micas and will stick to them.

 

[psfred]

It will promote DOS badly, and can be toxic if it becomes chealated with something. DOS would be much more problematic as I don't expect you would be eating much of the soap....

I'd use micas.

 

[nframe]

I have listened to all your advice and it is now in the bin. That will teach me to try and experiment! Luckily, it was not expensive. I will stick to micas in the future.

Thank you all for your time.

 

[lmosca]

I have listened to all your advice and it is now in the bin. That will teach me to try and experiment! Luckily, it was not expensive. I will stick to micas in the future.

Oh I wouldn't chuck it straight away. There are other uses for it!
If you like painting or know somebody who likes old painting techniques, basic copper carbonate is a very precious pigment for oil painting that it is used for light bluish-green, hazy coatings. (Check works from Rubens).
It is also a fungi- and algicide, you can suspend it in water and spray it on grapes, potato plants, tomato vines, and I believe apples and peaches as well. It is approved for organic culture, whatever that means.
Check for the usage of Bordeaux mixture and Burgundy mixture.

Also, a teensy tiny bit in planter or vase collecting saucers keeps at bay mosquito larvaes during the summer!

I believe that since you have it, you should try and give it a dignified end!

Best,
L.

 

[Holly8991]

I did win a chem award in college but.....i cant remember much of it because it was a long time ago. In my day job we use and have used over the years multiple forms of copper to treat wood. The EPA cracks down on the best forms of copper being dissolved for our usage. I would totally shy away from any type of copper in my soaps.
In wood it still makes a slight to large copper color on wood so ....

 

[cjisler]

Pretty sure it will accelerate DOS.

 

[nframe]

Thank you all for your input.

I will definitely not use it for soap but I like the idea of "a teensy tiny bit in planter or vase collecting saucers keeps at bay mosquito larvaes during the summer!". I always get badly bitten by mosquitoes or other insects (my husband never gets a single bite - it's not fair!). Do you think it would work if I placed that saucer on the coffee table?

 

[lmosca]

Copper is not a repellant for mosquitoes, but it simply kills the larvae (at high concentrations directly, at lower concentration by killing the algae that they use as food in stagnant water). It's an old trick to use copper wire in the vase saucers or even to put a copper-containing coin, to avoid the involuntary and perfectly natural breeding of mosquitoes, after watering plants. Clearly the best thing would be to empty the under vases after all the water has collected, but for big planters, that's clearly not possible. Here the natural acidity of water draining from the soil (humic acids) will dissolve the copper (or the copper carbonate) and will kill algae and mosquito instars (larvae).

According to this quick guide:
https://www.rockcreek.com/the-complete-guide-to-insect-repellent
the most effective repellents for mosquitoes (and other bugs) are DEET, Picaridin, and oil of lemon eucalyptus (not the essential oil, which vanishes too quickly).

 

[nframe]

Copper is not a repellant for mosquitoes, but it simply kills the larvae (at high concentrations directly, at lower concentration by killing the algae that they use as food in stagnant water). It's an old trick to use copper wire in the vase saucers or even to put a copper-containing coin, to avoid the involuntary and perfectly natural breeding of mosquitoes, after watering plants. Clearly the best thing would be to empty the under vases after all the water has collected, but for big planters, that's clearly not possible. Here the natural acidity of water draining from the soil (humic acids) will dissolve the copper (or the copper carbonate) and will kill algae and mosquito instars (larvae).

According to this quick guide:
https://www.rockcreek.com/the-complete-guide-to-insect-repellent
the most effective repellents for mosquitoes (and other bugs) are DEET, Picaridin, and oil of lemon eucalyptus (not the essential oil, which vanishes too quickly).

You are a real mine of information! Thank you.

 

[Nita]

I wouldn't use it for several reasons.

1) Color intensity: the refractive index of basic copper carbonate (you cannot have copper carbonate alone, it is an equimolar mixture of Copper carbonate x copper hydroxide) is quite low, at 1.66, that is, it's a very transparent pigment. For comparison, iron oxides are around 2.5, up there with titanium dioxide. That's why it takes a little of those to make a good color. With copper carbonate (malachite green) you'll have to use a lot.

2) Copper carbonate is unstable in acid and alkaline conditions, in acid will decompose to form the aquo-ion (a very pale blue) [Cu(H2O)n]2+, in strongly alkaline solutions it will dissolve to form hydroxocuprates [Cu(OH)4-n(X)n]2-, which are a deep blue. That is the color will morph over time, and will not be reliable.

3) Copper ions might be catalytic for fatty acid oxidation, that is you will literally promote rancidity of the oil, soap and formation of DOS. Scrap the might, they are for sure, as they are used for reactions on double and triple bonds in chemistry.

4) Toxicity issue, even if it's a rinse off product. Not only, copper compounds are extremely toxic for aquatic life, though the doses you will drain in the sewage are not even comparable to what we discharge from industries. Though, it's not an excuse to do it

Very good information. I believe copper carbonate could help promote DOS.