United States Nuclear Regulatory Commission - Protecting People and the Environment


A radioactive isotope of hydrogen. Because it is chemically identical to natural hydrogen, tritium can easily be taken into the body by any ingestion path. It decays by emitting beta particles and has a half-life of about 12.5 years. For related information, see the Fact Sheet on Tritium, Radiation Protection Limits, and Drinking Water Standards.

Page Last Reviewed/Updated Monday, April 10, 2017