An infographic detailing what potassium iodide (KI) is, how it works and when you should or should not take it. From the document: "KI is a pill or liquid that can be used in radiation emergencies that involve radioactive iodine. KI contains non-radioactive iodine. Non-radioactive iodine helps prevent radioactive iodine from being absorbed by the thyroid gland."
Centers for Disease Control and Prevention: http://www.cdc.gov/