ASTM D5072-26

1.1 This test method is capable of measuring radon in drinking water in concentrations above 2 Bq/L. The laboratory can vary the method’s measurement capabilities through its selection of analysis parameters, including count durations and decay times. The laboratory is responsible for validating its implementation of the method as described in 15.2.

1.2 This test method may be used for absolute measurements by calibrating with a ²²⁶Ra standard or for relative measurements by comparing the measurements made with each other.

1.3 This test method is used successfully with drinking water samples and Type III reagent water conforming to Specification D1193. It is the user’s responsibility to ensure the validity of this test method for waters of untested matrices.

1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

5.1 Radon occurs naturally in ground water. Its longest-lived isotope is ²²²Rn, with a half-life of ~3.8 d. Radon in water can present a health risk through ingestion, but there is typically a greater risk from inhalation of the radon released from water into the air by showering and other household activities. This test method is optimized for measurement of ²²²Rn.