Checklist To Ensure a Valid Real Estate Radon Test
Check these items to ensure a valid radon test.
For more information about radon testing for a real estate transaction, please consult our publication Pennsylvania's Home Buyer's and Seller's Guide to Radon (PDF).

Is the tester (person placing and/or retrieving the test device) certified as a testing individual or DEP listed as a testing employee of a certified firm?

To verify certification:
  • call DEP at 1 (800) 23-RADON,
  • ask to see the tester's current DEP I.D. card, or
  • a copy of the current DEP certification certificate.
  • refer to the Radon Services Directory to see if the name is listed
Test Criteria
  • If the test device is placed for greater than two days and less then 90 days, were closed house conditions maintained during the entire testing period?

    NOTE: DEP considers closed-house conditions to be maintained when all doors and windows are closed (except for normal entrance and exiting)and all fans and other external/internal ventilation systems (except the furnace) are not in operation.

  • If the test device is placed for less than four days, were closed-house conditions maintained for at least 12 hours prior to the test and for the entire testing period?

  • Is the test device placed at least:
    • 20 inches off the floor? and,
    • 4 inches from other objects? and,
    • 1 foot from external walls? and,
    • 3 feet from windows or other potential openings in the exterior walls?

  • Is the test device placed in the lowest-livable area?

    NOTE: DEP considers the basement, if any, to be the lowest-livable area if it can be used as a living area without major structural changes. This is true even if the basement is not currently renovated into a finished-living space, because the buyer may renovate and use the basement as a living space. Naturally, basements with ground floors or low ceilings would need major structural changes and, therefore, would not be considered the lowest-livable area.

  • If it is a short-term test using either a charcoal or electret test device, were two test devices placed:
    • simultaneously and side-by-side
      -or-
    • sequentially and in the same location?
    • Was the test device placed for at least 48 hours?

  • If an active mitigation system is installed in the house, was the fan operating for at least 24 hours prior to performing the test and during the entire testing period?

  • Does the tester demonstrate or provide information to ensure that testing conditions are not violated?

  • For test devices placed simultaneously or sequentially, was the average used to determine the need for mitigation?

The Environmental Protection Agency (EPA) recommends that you take action to reduce your home indoor radon levels if your radon test is 4 pCi/L or higher. For more information about reducing your radon levels, please consult our publication Pennsylvania's Consumer's Guide To Radon Reduction (PDF).

Free Services Available from DEP
  • A toll-free number, 1 (800) 23-RADON, with technical personnel to answer questions about any aspect of radon or radon certification.

  • Radon Information Packets. These packets include:
  • Easy to follow radon mitigation checklists, maps of Pennsylvania and U.S. radon zones.

  • If an active (fan-powered) radon mitigation system has been installed in your home within the last year, you are entitled to receive a free, long-term radon test kit (Alpha Track Detector). Please call 1 (800) 237-2366 or (717) 783-3594 for further details.

  • All Pennsylvanians who have tested their homes or other buildings for radon and found screening levels greater than 100 pCi/L, are entitled to receive a free short-term confirmation test kit from the Bureau of Radiation Protection. This test kit will be mailed to those eligible by express mail. For this free service, please call 1 (800) 237-2366 or (717) 783-3594 for further details.
Facts about Radon
  • Estimated lung cancer deaths per year in Pennsylvania due to residential radon exposure is between 860 - 3,800.

  • An estimated 40% of Pennsylvania homes have radon levels greater than the EPA guideline of 4 pCi/L.

  • Forty-nine of Pennsylvania's 67 counties have a predicted average indoor level greater than 4 pCi/L.

  • About 270,000 single homes in Pennsylvania, with about 750,000 occupants, are expected to have radon levels greater than 20 pCi/L (over five times greater than the EPA action level of 4 pCi/L).

  • Only about 10% of homes in Pennsylvania have been tested.

  • Radon Test Data by Zip Code for Pennsylvania
    • Find radon test averages for Pennsylvania zip codes. To generate a report, click the above link, then enter the zip code and click the 'View Report' button. The test location within the home, number of tests within the zip code, the maximum and average radon test values are all displayed.