Copper Sulfate (Pentahydrate)

Description

Chemical Class and Type

Copper sulfate, also known as cupric sulfate, is an inorganic salt with the chemical formula CuSO₄. It exists in various forms, including basic copper sulfate, copper sulfate monohydrate, copper sulfate pentahydrate, and copper sulfate anhydrous. When mixed with calcium hydroxide, it forms Bordeaux mixture, a widely used fungicide. Copper sulfate has been used since the 1700s and was first registered for use in the United States in 1956.

Properties

Copper sulfate is highly soluble in water, and the copper ion is the component responsible for its toxicological effects. Copper is an essential mineral, with a recommended dietary allowance of 900 µg/day for human adults. It is also a ubiquitous element found in the environment, foods, and water sources.

Uses

Copper sulfate is used as a fungicide, algaecide, root killer, and herbicide in both agricultural and non-agricultural settings. It is also used as an antimicrobial and molluscicide. In industrial applications, it serves as a drying agent, additive for fertilizers and foods, and in various manufacturing processes. Some products containing copper sulfate can be used in organic agriculture.

Safety and Regulation

Pesticides containing copper sulfate monohydrate and/or copper sulfate anhydrous have been cancelled by the United States Environmental Protection Agency (U.S. EPA). Signal words for products containing copper sulfate may range from Caution to Danger, depending on the toxicity of the formulation. It is important to follow label instructions when using copper sulfate products.

Mode of Action

Copper ions in copper sulfate bind to protein molecules in fungi, algae, and mollusks, causing protein denaturation and cell damage. In non-target organisms, copper plays a role in oxidative stress and can lead to toxicity at high concentrations.

Toxicity in Animals

Animals, particularly sheep, can be sensitive to copper sulfate. Signs of toxicity include diminished appetite, diarrhea, vomiting, and abdominal pain. Ingestion of large doses can lead to tissue corrosion, shock, and death. Dogs, especially certain breeds, are also susceptible to copper poisoning.

Toxicity in Humans

Human exposure to copper sulfate can result in symptoms such as metallic taste, nausea, vomiting, diarrhea, and abdominal pain. Ingestion of large amounts can lead to organ failure and other serious health effects. Inhalation exposure can cause respiratory irritation, while dermal exposure may result in skin irritation.

Fate in the Body

Copper from ingested copper sulfate is absorbed by the small intestine and distributed to various organs, primarily the liver. It can exist bound to proteins or as free copper in the bloodstream. Excess copper is excreted primarily through bile.