Iodine is used as a catalyst for making acetic acid. Animal feed also has iodine in it for nutrition. Iodine is used for a disinfectant. Tincture of iodine is a common iodine disinfectant. Iodine can be used to prevent thyroid cancer after a nuclear explosion. After a nuclear explosion, radioactive iodine fills the air. The radioactive iodine easily goes into the thyroid and causes cancer. When people take iodine tablets, it fills up the thyroid with non-radioactive iodine which prevents any radioactive iodine from coming in.