B 1871 Bismuth(III) oxide, powder, 10 μm, 99.9% Cas no 1304-76-3 - used in radio frequency shielding, compound for catheters and other medical tubing products. B 1871 Bismuth(III) oxide, powder, 10 μm, 99.9% Cas no 1304-76-3 - used as solid electrolyte because of its high thermal expansion property.