Barium sulfate, with the chemical formula BaSO4, is a chemical compound composed of barium (Ba) cations and sulfate (SO4^2-) anions. It is a white crystalline solid that is practically insoluble in water and most organic solvents. Barium sulfate occurs naturally as the mineral barite or can be prepared synthetically.

Some key properties and uses of barium sulfate include:

1. Radiopaque Contrast Agent: Barium sulfate is widely used as a radiopaque contrast medium in medical imaging procedures, such as X-ray examinations and computed tomography (CT) scans. It is safe for ingestion and helps outline the gastrointestinal tract, allowing doctors to visualize the digestive system during medical imaging.
2. Paint and Coatings: Barium sulfate is used as a filler or extender in paints, coatings, and plastics to improve their properties, such as opacity, brightness, and resistance to fading.
3. Drilling Fluids: It is used in the oil and gas industry as a weighting agent in drilling fluids to control well pressure and stabilize the borehole.
4. Pigment: Barium sulfate is used as a white pigment in certain applications, such as in artists’ paints and coatings.
5. Paper and Rubber Industries: It is used in the paper and rubber industries as a filler to improve various properties of these materials.

Barium sulfate is generally considered non-toxic and safe for ingestion when used as a contrast agent in medical imaging procedures. However, as with any fine particulate matter, care should be taken to avoid inhalation of dust during handling.

Because barium sulfate is chemically inert and insoluble in water, it does not pose significant environmental hazards or risks of leaching into water bodies.

As with any chemical compound, safety precautions should be followed when handling barium sulfate in its powdered form to prevent the inhalation of dust particles. When used as a contrast agent in medical imaging, it is administered under controlled conditions by trained medical professionals.