Copper sulphate is an inorganic compound of Copper and Sulfur with the chemical formula CuSO4. Its striking bright blue colour is visually captivating. It is also known as Cupric Sulfate, Copper Sulfite, blue vitriol or Bluestone. It’s effective at killing fungus and bacteria in crops.

Its raw material is the basis of many other copper compounds. It has a wide variety of uses, including multivitamin/mineral supplements, paints, metalwork, medicine, fungicide/algaecide, pipe cleaner, and much more. The toxicity of copper depends on the amount of copper present. 


  • Fertilizer & Fungicide
  • Water Treatment
  • Pipe Cleaner
  • Pesticide
  • Etching
  • Algaecide
  • Root Killer
  • Crystal Formation

Copper Sulphate as Water Treatment

Copper sulphate can be used as an algaecide water treatment to rid ponds and lakes, and swimming pools of excess algae. High amounts of algae can cause other issues in the water and copper sulphate is a safe way to treat the water without compromising ecosystem sustainability.

It is usually not toxic to fish except in koi, goldfish, and trout. The alkalinity of the water should be over 50 ppm when using copper. If the alkalinity is any lower than this, there is a risk of copper poisoning.

Health Risks

According to the United States Environmental Protection Agency (EPA), copper sulphate pentahydrate is moderately toxic if ingested.

  • Acute overdose: severe gastrointestinal tract effects
  • Long-term overdose: Experience symptoms similar to Wilson’s disease

Copper may be present in drinking water. At concentrations of 4 mg/L, volunteers experienced nausea and at 6 mg/L participants experienced vomiting. According to the US EPA, the maximum amount of copper allowed in drinking water to be considered safe is 1.3 mg/L.

Wilson’s disease is a rare genetic disorder that prevents the body from eliminating copper and can be fatal without treatment. However, studies on mice have demonstrated that exposure to copper sulphate does not cause Wilson’s disease.

When copper sulphate was used as a pesticide, exposure to it for periods greater than 10 years increased the risk of renal cancer.


Copper sulphate, though effective for many various uses, is toxic to humans and easily absorbed through the skin. This is why proper handling and protective equipment are so important when using copper sulphate. You should avoid any contact with the skin by wearing protective gloves. If copper sulphate does get on your skin, it can cause itching and permanent yellow discolouration.

At Bisley International, we carry Copper Sulfate which can be applied as a solution to soil or foliage. To find out more about our product range or if you have any questions, contact us.