Iodine-125 (125I) is a radioisotope of iodine which has uses in bioassays, nuclear medicine imaging and in radiation therapy as brachytherapy to treat a series of conditions, including uveal tract melanoma, prostate cancer and cerebral tumors. It is the second longest-lived radioisotope of iodine, after iodine-129. Iodine125 tungsten radiation shielding can shield the radiation released from the these applications of iodine125.

In the situation of producing and using iodine125, it is necessary to take steps to prevent iodine125 from volatilizing into the surrounding air, to avoid it polluting the environment.Iodine125 tungsten radiation shielding is the best choice. The effective half life of iodine-125 is 59.43 days and it decays to an excited state of Te-125 by orbital electron capture. This state is a lower punch state that decays immediately byγdecay with a maximal energy of 35 keV. Some of the excess energy of the excited Te-125 may be internally converted to ejected electrons (also at 35 keV),or to x-rays (from electron bremsstrahlung), and also 21 total Auger electrons, which are produced at the low energies of 50 to 500 electron volts.

Iodine125 tungsten radiation shielding has high density and great shielding properties. It can shield the radiation released from the the application of iodine125 in a high degree. so as avoiding the radiation harming human.