Overview of Testing Procedures

Only an individual trained and certified in EPA approved radon measurement protocol knows the proper conditions, test devices, and guidelines to obtain reliable radon tests. He or she will evaluate the home and ensure that the procedures necessary to obtain reliable results are utilized.

In addition, a certified test measurement professional will explain proper testing conditions, and the necessity of cooperation of occupants during testing. The tester will analyze and report results. By using an independent, third party tester that is certified to perform test measurement, results will be provided by someone not involved in the real estate transaction.

For purposes of real estate transactions, radon test professionals often utilize what is called a "short-term test" to determine the radon potential of a home. These test devices are placed in a building for a minimum of 48 hours.

Both passive and active test mechanisms are available. Passive tests do not require electricity but do require sending the test to an approved laboratory for analysis. They usually consist of either an activated charcoal device or an alpha track detector. Active radon tests require power to operate, and usually refer to "continuous monitors" that will give results over a set period of time and indicate changes in radon concentrations.

Proper short-term testing is dependent on correct placement and conditions within the home during the test. "Closed-house conditions" are very important! The windows and doors must be kept closed (except for normal entry and exit) a minimum of 12 hours before and during testing.

In the case of real estate transactions, the test device must be placed in the lowest area of a home that is "suitable for occupancy." Brokers and agents must discuss this point with their clients and customers so a decision can be agreed upon, based upon the future use of the dwelling by the buyer. [For example, if the house in question has a finished basement that has not been used by the seller but will be used by the buyer, this would be the best location for the test.] Crawl spaces are not appropriate test locations. Areas in the home with high humidity levels and increased ventilation are also not good locations (such as bathrooms and kitchens). A test device must be placed at least 20 inches above the floor, in a location where it will not be disturbed.

If radon concentrations are unacceptable to a buyer - and certainly if they are above 4 pCi/L - the home should be mitigated.

Check Lists

If high levels of radon are found during a real estate transaction, the parties involved will have to discuss the timing and costs of mitigating the home. This is no different than discussing leaky roofs, broken stairs, or cracked windows!

The EPA has provided a checklist that should be carefully followed in order to obtain the most accurate radon measurement results. A radon tester should be able to verify that the following steps have been taken. If this is not possible, a new radon test should be performed:

- Prior to testing, occupants were notified regarding the importance of proper testing conditions, and given written instructions or information explaining directions.

- If a homeowner or buyer took the measurement, the test was performed with a radon measurement device listed with the Radon Measurement Proficiency (RMP) Program, and manufacturer's instructions were followed.

- When performed by a professional, he or she is a NEHA or NRSB-listed individual. The tester's ID number and organization should be clearly visible on the radon test report.

- The test should include methods to prevent or detect interference with both testing conditions and the test device.

- The radon test is for at least 48 hours long. (Some devices must be placed for more than 48 hours.)

- The EPA recommends that initial short-term radon testing be performed under "closed-house conditions". This means all windows were kept closed and except for normal entry and exit, exterior doors have been shut.

- Fans or other machinery bringing air in from the outside should not be running (unless part of an existing permanent radon mitigation system). The home's heating and cooling systems should operate normally during testing, using air conditioning units that only re-circulate interior air. Evaporative coolers (such as swamp coolers) are to be off, in addition to 'whole' house fans.

- For short-term tests, closed-house conditions must be maintained for at least 12 hours BEFORE and during the tests.

- Test devices should not be disturbed at any time during the test.

- If a radon mitigation system is installed in a home, the EPA recommends that follow-up testing be performed no sooner than 24 hours nor later than 30 days following completion and activation of the mitigation system. To avoid the appearance of conflict of interest, the EPA requires that the mitigation contractor shall recommend to the client that a mitigation system effectiveness test be conducted by an independent RMP or state certified testing firm or by the client.

- The EPA recommends follow-up testing after system installation every two years.