Colorless or white crystals having a faint odor of iodine, used as an expectorant. This form of potassium is recommended for use following exposure to radioactive iodides downwind from a nuclear reactor accident. The rationale is that it blocks the uptake of radioactive iodides by the thyroid gland, thus preventing or decreasing the chance of developing cancer of the thyroid many years later.
To augment the velocity or sensitivity of the emulsion within the x-ray film, a profoundly receptive negative substance is incorporated into the potassium bromide, thereby enhancing its overall performance.