NC State Extension

Self-Testing for Radon in a Home Using Test-Kits

Add picture of a test kit…….

Homeowners can test their home for radon in 2 ways. One is to hire professional services. Detailed information regarding this is available under the sub tab “Finding qualified professionals to fix radon in a home”.

Second option is to buy a test kit and perform the test on one’s own.

Radon test kits are of two types: short-term (3-4 days) and long- term (3-12 months). The short-term kits are quite inexpensive and in the range of $15- $30. These provide quick results.The long term kits are more expensive but provide a better idea of average radon levels in a home. Short-term kits are the ones a homeowner should use when testing a home for the first time. EPA recommends Whether you test for radon yourself or hire a state-certified tester or a privately certified tester, all radon tests should be taken for a minimum of 48 hours…”

Proper Testing Conditions (essential to getting accurate results)(EPA, 1993)

1. Correct placement of test kit is important to get accurate results. The kit should be placed in the most often used room of a home and in the lowest occupied level of the home. This might be a bedroom, family room, living room or a play area. However, it CANNOT be a laundry room, kitchen or bathroom.

2. The kit should be placed at least 20 inches above the ground and 4 inches away from any other object.

3. It should be at least 3 feet away from doors, windows or any other “openings” to the outdoors.

4. If the room has no doors or windows, the kit should be placed at least more than 1 feet away from the building’s exterior wall.

5. If the kit is being suspended in the air, it should hang so as to be in the general breathing zone of most people i.e. 6-8 feet from the floor.

6. The kit should not be disturbed during the entire testing period. It should also be kept away from heating and cooling vents, fan, direct sunlight, fireplace.

3. The home must be closed 12 hrs before the test begins and for the entire duration of test. This means all windows of the home and doors should be kept closed at all times except when entering or leaving the home under normal circumstances.

4. Minimum 48 hours testing is a must.

Short-term or Long-term test?

For first time testing, short-term kits are ideal. These can provide a quick initial estimation of radon levels in a home. Long-term test provide results for average year round conditions. EPA recommends the levels to be below 4 pCi/L.

  1. If the results are below 4 pCi/L  no follow up action is needed.
  2. If results find radon levels between 4 pCi/L to 10 pCi/L, EPA (1993) recommends a second follow-up test which could be either long-term or short-term. If the long-term test is done and its value is found at 4 pCi/L or higher, a mitigation action is recommended.
  3. If results find radon to be above 10.0 pCi/l , a second short-term test is recommended by the EPA (1993). At higher levels it is desirable to take the mitigation (reduction) action quickly. Then waiting for a long term test is not seen as a good option.

For both steps 2 and 3 when a second short-term test is done, an average of the two short-term tests is taken and if this comes to be 4 pCi/L or higher, than mitigation actions need to be taken by the homeowner (EPA, 1993).

Protocols for Radon and Radon Decay Product Measurements in Homes is an excellent guidance document published by EPA (1993) on how a home should be tested for radon. It can be accessed here. For quick reference,  important aspects of home testing can be found here.

Where to get a short-term test-kit ?

  •  The best option is to call one’s state radon office and find out if they provide the kits for free or at a discounted price under their radon program. January is National Radon Action Month and many state radon programs give away free test kits on first come basis to the residents.
  • If not, these can be purchased online for a discounted price under the National Radon Program Services housed in Kansas State University.
  • Lastly, the kits might be available at the local home improvement stores and purchased from there.

Note: If a person is buying or selling a home, it is recommended that professional services be used for testing rather than the self test kits. Here is a good video by U.S EPA for home buyers and sellers providing useful information on what either party should know about radon before a home transaction