Radon-Reporter-2026-Issue-1FINAL

18 | APRIL 2026 Increasing RRNC Effectiveness and Accountability Reducing radon exposure through building codes is one of the most effective, scalable public health strategies available. Expanding adoption and effective implementation of RRNC requirements ensures new homes are built with, at the very least, basic passive soil gas depressurization systems from the start. States and tribes play a critical role in protecting communities from radon exposure, the leading cause of lung cancer among non-smokers. Their leadership in advancing RRNC code adoption is key to interrupting the cycle where more new homes cause radon exposure. Code Adoption Webinar and Toolkit The Conference of Radiation Control Program Directors launched a government-to-government campaign to provide tools to state and tribal radon program leaders to support adoption of building code requirements for radon control systems in new buildings – also known as Reducing Radon in New Construction (RRNC). The effort was kicked off with a January webinar for states and tribes that featured presentations on how RRNC works, the International Residential Code’s radon appendix, RRNC adoptions across the US, how state radon programs have collaborated with code officials, and the viewpoint of a code official. The Code Adoption Toolkit, which includes links to the webinar recording, slides, talking points, references, and code adoptions, is posted at https://radonleaders.org/Portal/RRNCtoolkit RRNC Adoptions Update The CRCPD E25 Committee on Radon researched the status of state and local code adoptions of the radon appendix, including which version (year) was adopted. Stakeholders are encouraged to check out the resultant table for state and local adoptions and send any needed updates to nationalpolicy@indoorenvironments.org Multiple Versions of the Radon Appendix It’s no longer just Appendix F (keeping the same name would be too easy). The 2021 version is called “Appendix AF.” The 2024 version is called “Appendix BE.” Progress from radon stakeholder advocacy has added complexity. After remaining unchanged for two and a half decades, the radon appendix received seven changes: • 2021 Appendix AF - addition of the testing requirement • 2024 Appendix BE - during the past few years: aligned the subslab soil-gas retarder specification during the past few years with IRC’s subslab vapor barrier, exempted well-drained soils from sand requirement • 2027 Appendix BE - eliminated the radon zone map, added fan space, added vertical pipe, added ANSI/AARST RRNC as an optional pathway RADON IN NEWCONSTRUCTION