How can I be sure that my radon test is done by a certified professional and that it is accurate?


How can I be sure that my radon test is done by a certified professional and that it is accurate?

Asked by Allen Fields

Our Yellow Pages list a lot of "home inspectors" that provide radon testing. But I understand that the EPA has a proficiency test you are suppose to pass to demonstrate your knowledge of the proper procedures to do a test under. But most real estate agents I talk with about this seem to be "clueless" (or apathetic) on this service that could impact whether I buy the house or not!

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Michael Holcomb's picture

The EPA's Radon Proficiency Program was discontinued on September 30, 1998 due to a lack of funding.

As a former participant in this program I was sorry to see it discontinued because the market was soon flooded with "radon experts".

Finding a qualified radon professional

  • You should check with you local county health department to see if they keep a list of qualified testing companies.
  • If not check with the state office of the EPA, which you can find here.

If neither agency offers any assistance you might interview the testing company and ask them for a copy of their testing protocol, calibration certificates (for continuous radon monitors), insurance and number of homes tested.

You are looking for professionals that will not be offended by your questions.

  • What you don't want is someone loosely affiliated with a real estate agent that picks up a charcoal canister from Home Depot and does the test without any protocols or training.
  • Find a testing company that uses a continuous radon monitor with certification of calibration within the past 12 months.

The results should show radon levels fluctuating over the course of the test - that's normal. What you are looking for is an average over the course of the test under 4 picocurries per liter of air.

Interpreting the results

I always tell my clients that short term tests are only an "indicator" of a potential radon problem.

  • If you test under 4 pCi/liter or air you might still have a problem that didn't show up because the house did not meet closed house conditions or the test was otherwise compromised.
  • If your home tests over 4 pCi/liter of air you might NOT have a problem. A short term test result between 4 and 10 should trigger a follow-up test (short term for real estate transactions) or long term (90+ days) for owner occupants.

A high radon level should not necessarily end a real estate transaction.

Radon, in most cases, can be mitigated by installing a sub slab ventilation system. Costs vary from region to region and it depends on the type and size of your home.

Every homeowner should test their home for radon every two years to be safe. You can self test ( using charcoal canisters to help determine if professional testing is warranted.

For more information:

Read "Why aren't more builders building homes with radon-resistant construction techniques? They fix radon and lower moisture!" a Q&A answered by Ray Pruban.