Barium sulfate

Barium sulfate (CAS 7727-43-7), also sold as blanc fixe in its precipitated form, is an inorganic mineral used as a dense, chemically inert filler and opacifying agent.

Where is Barium sulfate used?

• Coatings and paints: improves surface gloss, film hardness, and opacity without interfering with pigment systems
• Automotive primers and high-end decorative finishes
• Plastics: weighting and stiffening filler in polypropylene, PVC, and engineering polymers
• Rubber: inert extender filler that maintains compound viscosity
• Pharmaceutical and medical imaging sectors use high-purity grades as a radiocontrast agent in gastrointestinal diagnostic procedures.
• Pulp and paper
• Lubricants
• Drilling fluids: increases density and hydrostatic pressure in the well, reducing the possibility of a blowout

Good to know: Precipitated grades offer tighter particle size distribution and higher purity, while natural grades are used in industrial and construction applications.

Typical specification

• Reflects both visible and ultraviolet light to a high degree.
• Can be produced synthetically by reacting barium compounds such as barium chloride with sulfuric acid or sodium sulfate.
• The synthetic production route is relevant for certain applications because it allows high purity and control over the particle size and shape.

Regulatory status

• The MAK value (as Ba, respirable fraction) is 0.3 mg/m³, with peak limitation category II(8) and pregnancy risk group C.
• Because of its very low solubility, it is not classified as a hazardous substance, unlike all other barium compounds.
• Listed in the USP, EP, JP and Martindale monographs.
• OSHA's exposure limit for dust in air is 15 mg/m³ over an 8-hour workday.

Frequently asked questions about Barium sulfate

What are the main industrial applications of barium sulfate?

It is used as an X-ray shielding material due to its increased radiopacity, and selected grades serve as fillers in adhesive and mastic formulations.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.