It has physical half-life of 1445 hours (60.2 days). However, the effective half-life is a function of the biological half-life of every I-125 compound. I-125 OIH (sodium ortho-iodide hyppurate) is used for testing. It has an effective half-life of 6 hours. By a nursing interruption of 2 days there is no risk of irradiation in the infant. For other I-125 compounds like I-125 HSA (Human serum albumin) and I-125 Fibrinogen 3 weeks of nursing interruption are recommended. Whenever the continuation of breastfeeding is desired, it is advisable to start pumping and milk may be used to feed the infant while nursing is being interrupted whether alone or together with formula. Once the test is over, mother’s milk may be pumped and storage in a separated freezer until it achieves 10 physical half-lives at which point the radiation has disappeared and milk become safe. Radiation level in breast milk can be tested. The shortest half-life radio-nuclide must be chosen whenever possible.