Sciencemadness Discussion Board

Hazardous chemicals

Wrecking Bereserker - 4-4-2019 at 10:17

I always thought Copper Sulphate was just a normal good boy but recently i heard it is toxic also is it true i mean any bad experiences?
Wikipedia says recommended exposure limit is 1mg/1m3 isn't that a very small amount?
Just about everything i read is saying that they are either toxic/carcinogenic/corrosive/hazardous if most of the things are this way how come average humans are not affected by the environment m?

Schleimsäure - 4-4-2019 at 10:54

Don't take the hypersensitive "everything is soooo evil and nasty" attitude of these days too serious.
Just apply common sense where it's due.

And don't be afraid of copper sulphate, just don't eat a kilo of it, which would not be possible anyway. Copper sulphate solutions were used to ingnite nausea in case of real digestive intoxication. I have still a 1960's hobby chemistry book from the former GDR where it is recommended to have a solution in your emergency lab med kit.
My brother told me once he thoght he intoxicated himself and took a good sip of CuSO4 solution in the 70s or so. He vomitted like there is no tomorrow.

[Edited on 4-4-2019 by Schleimsäure]

Ubya - 4-4-2019 at 11:16

everything is toxic in the right amounts, if you drink 7 liters of water in one session you probably die. i'm not saying to disregard every safety warning, just use common sense, for example don't drink heavy metal salts (copper sulphate for example), don't put your dirty hands to you face (eyes or mouth), etc
when you go to the restaurant you don't find a warning label near the plate that says "warning, sharp pointy metal objects can cause damage to flesh, eyes and major blood vessels if used incorrectly"
but you'll find the warning label on rat poison that says "don't eat it"
common sense, simple, if you have doubts, ask, simple as that

brubei - 4-4-2019 at 11:49

Several pathologies have been identified with worker who are exposed to high concentrations of CuSO4 particles. However CuSO4 is massively used in agriculture, even for feeding animals. So you can throw it in the sink without worrying, just protect yourself (mask) if you use fine powder for several days.

Edit: cheap copper salt may contains Nickel who is much toxic

[Edited on 4-4-2019 by brubei]

RedDwarf - 4-4-2019 at 11:57

Copper sulphate (combined with lime and water iirc) is "Bordeaux mixture" which was a permitted fungicide for fruit and veg with "organic" farming and gardening. I wouldn't worry about the safety, although that's probably your greatest risk of significant ingestion, but it does demonstrate that the organic label in farming is often far from what people suspect it to mean.

wg48temp9 - 4-4-2019 at 13:02

Quote: Originally posted by Wrecking Bereserker  
I always thought Copper Sulphate was just a normal good boy but recently i heard it is toxic also is it true i mean any bad experiences?
Wikipedia says recommended exposure limit is 1mg/1m3 isn't that a very small amount?
Just about everything i read is saying that they are either toxic/carcinogenic/corrosive/hazardous if most of the things are this way how come average humans are not affected by the environment m?


As I said previously you have look at the context of any number. In this case the 1mg/1m3 is the time weighted average maximum permisible limit in the work place for a worker over his working life, say 50 years, 8h a day 5 days a week 50 weeks per year. That's about 4m3 air breathed each working day say 4mg each working day. Which is about 12kg of copper over a working life time of 50 years. Thats a lot of copper. 1mg/m3 is less than 1ppm which is much smaller than 10ppm of chlorine in your previous post. However the maximum permissible limit (long term) for chlorine is probably much less than 1ppm.

So you could say that when breathed in long term, compared to chlorine copper is a lot less poisonous than chlorine.

[Edited on 4-4-2019 by wg48temp9]

Herr Haber - 5-4-2019 at 04:07

Bordeaux mixture is not permitted anymore in the EU ! Mushroom farms stopped using it long before though.
Happened around the same time when DCM and borax compounds started to disappear.
In reality (as it was the case with Ammonium Nitrate) agricultors still have massive amounts and are more than willing to sell.

In all these cases the main reason was not toxicity to humans but environmental concerns.

MrHomeScientist - 5-4-2019 at 06:35

Copper ions are pretty toxic to aquatic life, so I always react any copper solutions with baking soda rather than pouring them down the drain. Then you get basic copper carbonate which is a nice starting point for other copper salts. If you just want to get rid of it, heating with a propane torch will decompose it to black copper oxide which is even less hazardous. Or mix that copper oxide with carbon, and reclaim your copper metal!

unionised - 5-4-2019 at 09:34

IIRC the limit set by WHO for copper compounds in drinking water is due to taste, rather than toxicity.

fusso - 6-4-2019 at 09:39

Quote: Originally posted by unionised  
IIRC the limit set by WHO for copper compounds in drinking water is due to taste, rather than toxicity.
What taste is Cu2+?

Abromination - 6-4-2019 at 11:39

Quote: Originally posted by fusso  
Quote: Originally posted by unionised  
IIRC the limit set by WHO for copper compounds in drinking water is due to taste, rather than toxicity.
What taste is Cu2+?

It is bitter sweet with a hint of a chalky metallic flavor.

j_sum1 - 6-4-2019 at 21:55

Quote: Originally posted by fusso  
What taste is Cu2+?

Metallic, bitter, mouth-drying and gag-inducing. You will want to spit out your tonsils.
Gargle a little copper sulfate and you will see what I mean.

Abromination - 6-4-2019 at 22:43

Quote: Originally posted by j_sum1  
Quote: Originally posted by fusso  
What taste is Cu2+?

Metallic, bitter, mouth-drying and gag-inducing. You will want to spit out your tonsils.
Gargle a little copper sulfate and you will see what I mean.

Thats what I was trying to describe, just couldnt find the right words. Its almost like getting a drop of dilute hydrogen peroxide on your tounge but with a metallic taste.

fusso - 6-4-2019 at 22:51

That sounds gross and disgusting, I think I better not let it enter my mouth:o

unionised - 7-4-2019 at 01:21

Most people have found out what Cu++ ions taste like by handling copper coins, then eating stuff without washing their hands.

People generally learn to wash their hands.

fusso - 7-4-2019 at 01:42

Quote: Originally posted by unionised  
Most people have found out what Cu++ ions taste like by handling copper coins, then eating stuff without washing their hands.

People generally learn to wash their hands.
WTF thats fucking dirty!!!:o

Fantasma4500 - 27-8-2019 at 23:41

of what i recall it may cause anger issues, copper is modified by cadmium, i personally have experience with it affecting aggression through welding smoke from solid core wire, such wire is electrocoated with copper, but manganese in this wire is alloyed with 0.4% manganese usually (google manganism)
copper is necessary to balance out zinc in the body and vice versa, i wouldnt be very worried about copper but excess nutrients would typically act neurotoxic, leading to neurodegeneracy
ive been exposed to decent bunches of copper species also from dehydrating copper sulfate and even been in a cloud of copper smoke with no seeming effect on my health
i would say - not very worrying unless were talking chronic exposure

it can in large doses cause vomiting, like a teaspoon of copper sulfate
it gave me mild nausea the times i supplemented with copper in the form of copper acetate (appropriate dosage, heavily diluted)

teodor - 29-8-2019 at 05:02

According to wikipedia data for LD50 of ethyl alcohol and Cu2SO4 it seams that 20% Cu2SO4 (concentrated) solution has the toxicity of whiskey.

So, one can use this simple whiskey method to understand that data.

(Somebody have fear to keep even 10 bottles of it)?


For more toxic compounds you probably can use the aspirin method.



[Edited on 29-8-2019 by teodor]