Iodine absorbed by the body is almost completely stored in the thyroid gland and has a biological half-life of about 120 days. If the iodine is radioactive (I), it can irradiate and damage the thyroid gland in high doses during this time. Because the thyroid gland can only absorb a limited amount of iodine, prophylactic administration of non-radioactive iodine may result in iodine blockade. Potassium iodide in tablet form (colloquially known as "iodine tablets") reduces the uptake of radioactive iodine into the thyroid by a factor of 90 or more, thus acting as a radioprotector. All other radiation damage remains unaffected by taking iodine tablets. In Germany, the Potassium Iodide Ordinance (KIV) was enacted in 2003 to ensure "the supply of the population with potassium iodide-containing medicines in the event of radiological incidents".