Radon in Real Estate Testing Checklist

EPA's Radon in Real Estate Testing Checklist can help you through all of the steps for testing a home during this important time. If the seller or qualified tester cannot confirm that all of these items have been completed, you may need to test the home again.

Before conducting a radon test:

• Educate everyone in the home about the importance of radon testing. Make sure occupants understand why the test is being conducted and why following the testing conditions is important.
• Always use a certified radon professional during a real estate transaction.
• Plan for a two-day radon test.
• Begin “closed house” conditions at least 12 hours before the radon test begins. “Closed house” simply means do not leave windows or exterior doors open. Normal coming and going is okay.

During a radon test:

• Continue “closed house” conditions for the entire test. This means windows and exterior doors should not be left open. People can enter and leave the home normally.
• Operate the home’s heating and cooling systems normally.
• Turn off swamp coolers.
• Do not move, unplug or disturb the radon testing device.
• If the home has a radon mitigation system, make sure it is operating properly during the test.

After a radon test:

• The certified radon professional will provide a digital copy of the test results by email.
• Radon levels naturally vary throughout the day and night. The average radon level over the testing period is the important number.
• If the average radon level is 2.7 pCi/L or higher, radon mitigation is recommended.
  
  • To locate a certified mitigation professional.
  • See How to Fix a Radon Problem/Radon Mitigation.

"Many Realtors place special importance on radon levels at 4.0 pCi/L or higher because some states use that number in their real estate regulations. In those states, a radon result at or above 4.0 pCi/L may require the seller to pay for mitigation. Nevada does not have those requirements. The EPA's 4.0 pCi/L action level is not a health-based number or a safe level of radon exposure. When it comes to radon, lower is better because lower exposure means lower risk."

– Chris Kelly, Senior Program Coordinator, Nevada Radon Education Program

Published by: Kelly, C., 2022, Radon in Real Estate Testing Checklist, Extension | University of Nevada, Reno. IP

An EEO/AA Institution. Copyright © 2026, University of Nevada Cooperative Extension.
A partnership of Nevada counties; University of Nevada, Reno; and the U.S. Department of Agriculture