Sciencemadness Discussion Board

Copper hydroxide safety?

Draeger - 14-6-2020 at 13:55

According to the German Wikipedia, copper hydroxide is fatal on inhalation, while the English Wikipedia doesn't really mention any particularly strong toxicity. Which is true?

Syn the Sizer - 14-6-2020 at 14:07

I can't say for sure but I do know that copper is an essential to health, in small concentrations.

the ThermoFischer SDS sheet also says fatal if inhaled.

http://fishersci.ca/shop/msdsproxy?productName=AA3273336&...

I wonder if it is because it is a hydroxide salt and on contact with your soft moist lung tissue reacts. Through ingestion it would produce CuCl2 and H2O, also toxic.

I would also assume it depends on how much you have inhaled as to whether its fatal or just unhealthy.

Draeger - 14-6-2020 at 14:14

Quote: Originally posted by Syn the Sizer  
I can't say for sure but I do know that copper is an essential to health, in small concentrations.

the ThermoFischer SDS sheet also says fatal if inhaled.

http://fishersci.ca/shop/msdsproxy?productName=AA3273336&...

I wonder if it is because it is a hydroxide salt and on contact with your soft moist lung tissue reacts. Through ingestion it would produce CuCl2 and H2O, also toxic.

I would also assume it depends on how much you have inhaled as to whether its fatal or just unhealthy.

Maybe. But then why are alkali hydroxides not rated fatal on inhalation?

I'm just looking for someone who can tell me if I can do stuff with it inside or not, to be honest.

Syn the Sizer - 14-6-2020 at 14:43

To be honest with you, until now I didn't know it was fatal on inhalation, I have done reactions with it twice inside, but I also made sure no dust was projected out.

As for the alkali hydroxides, its probably because they are highly soluble in water they may burn and scar your lungs but we would cough it out with phlegm, where many alkaline and heavy metal hydroxides are not.

Though in hind sight I do not know what heavy metal hydroxides would react with in the lungs, probably coats them with an impermeable copper (II) hydroxide layer suffocating you.

[Edited on 14-6-2020 by Syn the Sizer]

[Edited on 14-6-2020 by Syn the Sizer]

[Edited on 14-6-2020 by Syn the Sizer]

Draeger - 14-6-2020 at 14:45

Quote: Originally posted by Syn the Sizer  
To be honest with you, until now I didn't know it was fatal on inhalation, I have done reactions with it twice inside, but I also made sure no dust was projected out.

As for the alkali hydroxides, its probably because they are highly soluble in water where many alkaline and heavy metal hydroxides are not. Though in hind sight I do not know what heavy metal hydroxides would react with in the lungs, probably coats them with an impermeable copper (II) hydroxide layer suffocating you.

[Edited on 14-6-2020 by Syn the Sizer]

Ah, okay. Thanks. I hope I didn't breathe in too much, then. I'll be using carbonates when I can then in the future.

B(a)P - 14-6-2020 at 14:47

It is safe when handled appropriately. It has a similar inhalation toxicity to copper sulfate. Avoid generating dust when working with it. If you can't, then use a fumehood, if you don't have one use a particular respirator.

Syn the Sizer - 14-6-2020 at 14:52

Quote: Originally posted by Draeger  

Ah, okay. Thanks. I hope I didn't breathe in too much, then. I'll be using carbonates when I can then in the future.


Yes, me too, I had already decided to start using carbonates due to the continuous reaction, but this reinforces it.

Abromination - 14-6-2020 at 16:43

Copper hydroxide is fine, I have used it several times at home and worked with it in a first year high school chem lab. As a general rule, copper salts are toxic but only in quantities of which you are unlikely to encounter. You wont die if you inhale dust from copper hydroxide.

On a side note, it is usually better to use the hydroxide quite quickly after making it, it has a tendency of converting to the black oxide, especially in strong alkaline conditions.

Draeger - 15-6-2020 at 04:04

Quote: Originally posted by Abromination  
Copper hydroxide is fine, I have used it several times at home and worked with it in a first year high school chem lab. As a general rule, copper salts are toxic but only in quantities of which you are unlikely to encounter. You wont die if you inhale dust from copper hydroxide.

On a side note, it is usually better to use the hydroxide quite quickly after making it, it has a tendency of converting to the black oxide, especially in strong alkaline conditions.

Quote: Originally posted by B(a)P  
It is safe when handled appropriately. It has a similar inhalation toxicity to copper sulfate. Avoid generating dust when working with it. If you can't, then use a fumehood, if you don't have one use a particular respirator.

Still really weird that it's rated as GHS06 then. Copper sulfate is only rated as irritant.

Refinery - 15-6-2020 at 04:20

Quote:

INHALED
! The material is not thought to produce respiratory irritation (as classified using animal models). Nevertheless inhalation of dusts, or fume,
especially for prolonged periods, may produce respiratory discomfort and occasionally, distress.
! Inhalation of vapors or aerosols (mists, fumes), generated by the material during the course of normal handling, may be damaging to the
health of the individual.
! Persons with impaired respiratory function, airway diseases and conditions such as emphysema or chronic bronchitis, may incur further
disability if excessive concentrations of particulate are inhaled.
! Copper poisoning following exposure to copper dusts and fume may result in headache, cold sweat and weak pulse. Capillary, kidney, liver
and brain damage are the longer term manifestations of such poisoning. Inhalation of freshly formed metal oxide particles sized below 1.5
microns and generally between 0.02 to 0.05 microns may result in "metal fume fever". Symptoms may be delayed for up to 12 hours and
begin with the sudden onset of thirst, and a sweet, metallic or foul taste in the mouth. Other symptoms include upper respiratory tract irritation
accompanied by coughing and a dryness of the mucous membranes, lassitude and a generalised feeling of malaise. Mild to severe
headache, nausea, occasional vomiting, fever or chills, exaggerated mental activity, profuse sweating, diarrhoea, excessive urination and
prostration may also occur. Tolerance to the fumes develops rapidly, but is quickly lost. All symptoms usually subside within 24-36 hours
following removal from exposure.


I wonder if it's some sort of mishap. Some substances are regarded toxic, although LD50 requires significant uptake, in order of ingesting a teaspoon or even tablespoon worth of it. Such exposure would be not accidental by any means.

Inhaling dust, unless explosed to a huge cloud or pertaining conditions like in an industrial environment where particulate matter can remain airborne in large spaces, would result only in limited uptake. In amateur environment, stuff is usually handled in very small quantities, in partially enclosed vessels and briefly. I would rate such exposure in microgram or at max milligram scale, which does not pose hazard even if it were cyanide salt dust.

Many MSDS are designated for industrial occupation, where stuff is handled by the ton, chronically. Stuff that is acutely toxic but is quickly removed by the body pose only immediate risk and it can be regarded so that if it doesn't kill you right away, you will recover, but bio-accumulating substances can cause health issues even after single exposure.

Since copper sulfate is sold by the kilo at hardware store and it is used for lawn and soil treatment and even on horse and cattle feed, it or it's close relative hydroxide couldn't possibly be excessively fatal. Hydroxides usually quite readily convert to a more soluble form in acidic conditions.

woelen - 15-6-2020 at 05:02

@Refinery: good post.

Just use common sense with copper salts (and most other chemicals). Fear is not a good guide. There are only few chemicals, which require very special and careful treatment, and most amateurs do not have access to those chemicals. Examples of such chemicals are arsenic compounds, mercury compounds, certain organics.

In general: avoid exposure, work cleanly, try to avoid formation of airborne dust. After you have done experiments, clean up your tools and workbench with a moist tissue or towel.

Refinery - 15-6-2020 at 06:47

I would also suggest limiting contamination to a minimum by carefully planning the process step by step, preparing all required equipment on hand, and then decontaminating them and the workspace properly right away. For example when dealing with mercury compounds, do not handle them freely in your workshop, but isolate them as much as possible.

This might be a bit overkill, but one could actually consider making a plastic tabletop glovebox for some handlings. It could be moved to another location(outdoors?) and opened and equipment decontaminated there, or even a disposable one where the whole box can be wrapped and discarded without ever opening it. This would practically eliminate particular contamination on your workspace.