No Smell, No Warning: A Radon Check for Your First Rental

Before ordering a test, ask for any existing radon report. A verbal “it was checked” leaves useful details unanswered. Look for the property and unit tested, the floor and room, the test date and type, the reported result, and any follow-up work or retest. A report for another unit or level may not answer the question for this one.

EPA and the U.S. Surgeon General recommend testing all homes below the third floor. EPA’s current zone guidance also says to test regardless of where you live. If the report is missing, unclear, or does not match the space being assessed, ask your state radon program or a qualified radon tester what test applies. Follow CDC and EPA guidance if occupancy changes to a lower level or major work changes the building; those can be reasons to test again.

For a straightforward home, CDC describes testing with a kit or a radon tester and says to follow the device instructions for placement and return. For a multi-unit building, the procedure may depend on the layout and the purpose of the test. CDC’s general instruction is to place the device on the lowest level within the unit; a building-specific measurement protocol may call for other steps. Check with the state radon program or a qualified professional rather than guessing where one device should go.

EPA’s real-estate resources include a guide for tenants, along with information on qualified testers and mitigators. These resources can help you understand how a test is set up and what information a report should contain. They do not establish who is legally responsible for testing or repairs at a particular rental.

EPA recommends fixing a home when the radon level is 4 picocuries per liter (pCi/L) or higher. EPA also says to consider fixing levels between 2 and 4 pCi/L because there is no known safe level of radon exposure. These are EPA’s recommended health action levels; they do not, by themselves, determine the legal requirements for a particular property. Follow current state and local guidance, especially for a multi-unit building.

Testing procedures can include confirmation steps. CDC advises a second test after an initial short-term result; if the second test is short-term, use the average of both results when applying its guidance. If results warrant reduction, consult EPA and your state radon program, then use a qualified professional who understands the local requirements. CDC says radon reduction takes technical knowledge and special skills, so do not try to install a mitigation system yourself. Retest after work as directed and keep the follow-up result with the record.

A written record makes it easier to tell what was tested and what still needs follow-up. If the right procedure or next step is unclear, ask the state radon program or a qualified local professional for building-specific guidance. This is general property education, not legal, medical, or financial advice.