Copper sulfate is an inorganic compound with the chemical formula CuSO4. It exists in many different forms, depending on its degree of hydration. The anhydrous form is a light grey powder, while the hydrated copper(II) sulfate forms triclinic crystals that are blue in color. Several chemical tests use soluble copper(II) sulfate, including Fehling’s solution and Benedict’s solution for testing for reducing sugars, and in the Biuret test to determine protein content. It is also added to bookbinding glues to protect the paper from insect damage.

The most common source of copper(II) sulfate is from the mineral chalcantite. It is also produced synthetically, most commonly using copper metal and nitric acid or hydrogen peroxide. It is a popular raw material for the production of copper(II) oxide. This is a complex process, but it is inexpensive, and the product has excellent quality.

This chemical is moderately toxic by ingestion. It is absorbed through the skin, and ingested in sufficient quantities can cause liver and kidney damage. The acute oral LD50 in rats is 450 to 790 mg/kg.

Before pesticide products containing this chemical can be used, they must undergo laboratory testing for short-term and long-term health effects. This testing helps scientists judge how a given chemical might affect humans, domestic animals, and wildlife in cases of overexposure. NPIC’s Toxicity Classification descriptors and Signal Words help users interpret the results of these tests. This chemical has not been shown to be carcinogenic in experimental animals.