Skip to main content
Oregon.gov Homepage

Testing for Radon Gas

Radon is a health hazard with a simple solution.
Testing  is the first step. Luckily radon testing is inexpensive and easy - it should only take a few minutes of your time.  There are many kinds of low-cost, do it yourself radon test kits.

Short-term tests (2-90 days) and long-term tests (91 days-1year) are most commonly used to test for radon. Both types of test kits are usually found at your local hardware store or can be ordered online through organizations like The American Lung Association of Oregon. For more details, please visit Types of Radon Gas Testing.

If you are buying or selling a home, or if you simply prefer, you can hire a local qualified radon testing professional to do the testing for you. You can find a list of Oregon measurement companies here.


What your test results mean

Radon is measured by picocuries per liter of air (pCi/L). It is a naturally occurring substance that constantly surrounds us. The average outdoor radon concentration is 0.4 pCi/L, whereas the average indoor radon concentration is 1.3 pCi/L. It is important to note that there is no safe level of radon; however, it is long-term exposure to elevated levels of radon that pose the most risk. You can reduce the risk by lowering the radon level in your home.

The Environmental Protection Agency (EPA) has established an action level of 4.0 pCi/L, where it strongly recommends you mitigate your home.

EPA recommends you begin with a short term test for more immediate results. If your result is 4 pCi/L or higher, take a follow up test to be sure.

Depending on the results of your first test, follow up with either a long-term test or a second short term test. If your first test results are 4 to 8 pCi/L follow up with a long-term test. If your first test results were 8 pCi/L or above, follow up with another short-term test. If the average of your two short-term tests is 4 pCi/L or above, or the result of your long-term test was 4 pCi/L or above, fix your home.

If your test results are below the action level of 4.0 pCi/L, you may want to re-test in two to five years. You should test again if anything is done to the house that may change the air pressure like home renovation or the installation of new heating or air conditioning systems.


Testing reminders to ensure accurate results:

  • Follow the directions on your kit!
  • Testing should be done in the lowest livable area of your home (the basement if it is frequently used, otherwise the first floor).
  • Keep windows and outside doors shut except for normal entry & exit from the home.
  • Test placement should be in area away from drafts, high heat, high humidity and exterior walls of the home (kitchen, bathrooms, or laundry rooms).
  • Once the test is finished, send the test kit immediately to the laboratory specified on the package. Most test kits are manufactured to be accurate as long as they make it back to the lab within eight days after testing has stopped. A test processed after that point may give invalid results.
  • Don't forget to note down the test serial number!

IMPORTANT: Most short-term kits come with the postage pre-paid. If you know regular US Mail is slow in your area, we recommend you send it to the lab using 2-3 day US Priority Mail (or an overnight service like FedEx).

Your browser is out-of-date! It has known security flaws and may not display all features of this and other websites. Learn how

×