How to Test Granite & Radon

Purchase a charcoal radon-in-air testing kit. Testing kits are available from both private and government-based retailers, such as the EPA-recommended National Radon Program Services. For a link to the National Radon Program Services website, which provides both short-term and long-term testing kits and online test-reading capability, see Resources.

Place your charcoal testing kit on an open air surface. The kit should not be placed under any inverted containers, as this can skew the results. For rooms with multiple granite surfaces, more than one test kit may be necessary. Depending on your decision to use a short-term or long-term test kit, your wait time will range from three to four days for short-term or three to 12 months for long-term testing.

Read your radon test results. If you purchased a kit from a retailer that provides electronic results reading, such as National Radon Program Services, the results of your test will be electronically reported to the website and can be read online.

Compare your radon test kit's report with the EPA-approved level of 4 picocuries per liter, which is roughly equal to the amount of radon in outdoor air. If your granite is emitting levels of more than the recommended levels, you should contact your state's radon office or a private radon mitigation contractor. For a link to the EPA's list of all state radon offices, see Resources.