Copper Sulphate: Uses, Hazards and What Its SDS Must Say

Copper sulphate (also spelled copper sulfate) is the common name for copper(II) sulfate. The form most often traded is the pentahydrate, CuSO4·5H2O, CAS number 7758-99-8, a bright blue crystalline solid that dissolves readily in water. It is one of the most widely sold inorganic chemicals in the world, which makes it a staple for small traders and exporters, and a product that customers will ask you to supply an SDS for.

What copper sulphate is used for

Its uses fall into a few big groups, and the group your customer belongs to affects what your documents should say.

• Agriculture: a fungicide and bactericide, famously as Bordeaux mixture (copper sulphate plus lime) on vines, fruit trees and potatoes, and as a copper supplement for deficient soils.
• Animal feed: a trace-mineral source of copper, subject to feed-additive rules that cap permitted levels.
• Mining: an activator in froth flotation for zinc and other sulphide ores.
• Water treatment: an algaecide for ponds, reservoirs and cooling systems, where dosing must be carefully controlled.
• Electroplating and electronics: acid copper plating baths and the manufacture of printed circuit boards.
• Chemical manufacturing: a feedstock for other copper compounds, pigments, wood preservatives and catalysts.
• Laboratory and education: a reagent for testing, crystal growing and demonstrations.

How copper sulphate is classified

Under the GHS and the EU CLP Regulation, copper sulphate pentahydrate is commonly classified as harmful if swallowed (acute toxicity, category 4, H302), causing serious eye damage (category 1, H318), and very toxic to aquatic life with long lasting effects (aquatic acute 1 and chronic 1, H400 and H410). The signal word is Danger. The pictograms are the corrosion symbol (GHS05), the exclamation mark (GHS07) and the environment symbol (GHS09). Always check the current harmonised entry and your own supplier SDS, because classifications and concentration limits are revised over time.

The environmental classification is the one that surprises people. Copper is an essential trace element, but dissolved copper is highly toxic to fish and invertebrates at low concentrations. That is why an SDS for copper sulphate puts real weight on Section 12 (ecological information), Section 6 (preventing release to drains) and Section 13 (disposal).

Handling and storage

Dust is the main exposure route when handling the crystals or powder, so use local exhaust ventilation or a dust mask, chemical splash goggles and gloves. Avoid creating dust and keep food and drink away from the work area. Store in tightly closed containers in a cool, dry place, away from strong reducing agents and from alkalis. Copper sulphate is corrosive to some metals once dissolved, so use plastic or suitably lined containers for solutions.

For spills, sweep up solid material without raising dust, place it in a labelled container for disposal, and never wash residue into storm drains or waterways. Your emergency instructions in Section 6 should say this plainly.

What the SDS and label must show

A compliant copper sulphate SDS covers all 16 sections, and these points deserve attention: the CAS number and the correct hydrate form in Section 3, because the pentahydrate, the monohydrate and anhydrous copper sulphate are different products with different copper content; the physical state and solubility in Section 9; and transport information in Section 14, where copper sulphate is generally regulated as an environmentally hazardous substance for road, sea and air carriage. Check the current UN number and class with your carrier or the relevant transport code.

On the label, include the product identifier, supplier details, nominal quantity, the signal word, pictograms, hazard statements and precautionary statements. You can see the classification we hold for this substance on our copper sulphate pentahydrate page, and our guide to GHS label requirements explains how each element is chosen.

Frequently overlooked points

Purity and grade matter. Feed-grade, agricultural-grade and technical-grade copper sulphate differ in copper content and impurity limits such as arsenic and lead, so your specification and certificate of analysis should state the grade. If you sell a solution or a blend, such as a fungicide formulation, it is a mixture and you need to classify it from its components rather than reuse the pure-substance SDS.