B 1850 (OTTO) Bismuth iodide Cas 7787-64-6 - used as beta direct and digital detectors for medical imaging applications. B 1850 (OTTO) Bismuth iodide Cas 7787-64-6 - used as an ice nucleant. B 1850 (OTTO) Bismuth iodide Cas 7787-64-6 - used in electron microscopy to reveal synapses.