Home Buyer's and Seller's Guide to Radon is a publication by the Environmental Protection Agency. Used with permission under public domain and creative commons. Usage: Category Education; License: Creative Commons Attribution license (reuse allowed)
On this page: Radon Testing Checklist - For reliable test results, follow this Radon Testing Checklist carefully. Testing for radon is not complicated. Improper testing may yield inaccurate results and require another test. Disturbing or interfering with the test device, or with closed-house conditions*, may invalidate the test results and is illegal in some states. If the seller or qualified tester cannot confirm that all items have been completed, take another test.
Before Conducting a Radon Test: Notify the occupants of the importance of proper testing conditions. Give the occupants written instructions or a copy of this Guide and explain the directions carefully.
Conduct the radon test for a minimum of 48 hours; some test devices have a minimum exposure time greater than 48 hours.
When doing a short-term test ranging from 2-4 days, it is important to maintain closed-house conditions for at least 12 hours before the beginning of the test and during the entire test period.
When doing a short-term test ranging from 4-7 days, EPA recommends that closed-house conditions be maintained.
If you conduct the test yourself, use a qualified radon measurement device and follow the laboratory's instructions. Your state may be able to provide you with a list of do-it-yourself test devices available from qualified laboratories.
If you hire someone to do the test, hire only a qualified individual. Some states issue photo identification (ID) cards; ask to see it. The tester's ID number, if available, should be included or noted in the test report.
*Closed-house conditions means keeping all windows closed, keeping doors closed except for normal entry and exit, and not operating fans or other machines which bring in air from outside.
Fans that are part of a radon-reduction system or small exhaust fans operating for only short periods of time may run during the test.