ISO standards on test methods for water radioactivity monitoring

•The ISO published standards on test methods to monitor the radioactivity of drinking water.•ISO Standards used by test laboratories to carry out radionuclide measurements are presented.•The WHO refers to these test methods in its 4th edition of the Guidelines for Drinking-Water Quality.•National authority trusts the quality of data obtained by laboratories using common standards.

Water is vital to humans and each of us needs at least 1.5 L of safe water a day to drink. Beginning as long ago as 1958 the World Health Organization (WHO) has published guidelines to help ensure water is safe to drink. Focused from the start on monitoring radionuclides in water, and continually cooperating with WHO, the International Standardization Organization (ISO) has been publishing standards on radioactivity test methods since 1978. As reliable, comparable and ‘fit for purpose’ results are an essential requirement for any public health decision based on radioactivity measurements, international standards of tested and validated radionuclide test methods are an important tool for production of such measurements.This paper presents the ISO standards already published that could be used as normative references by testing laboratories in charge of radioactivity monitoring of drinking water as well as those currently under drafting and the prospect of standardized fast test methods in response to a nuclear accident.