Radon inspection

EPA's advice is to start with your state radon program. EPA requires states receiving indoor radon grants to list only providers credentialed through a state-run process, such as a state license, or through one of the two currently recognized national radon proficiency programs: the National Radon Proficiency Program (NRPP) and the National Radon Safety Board (NRSB).

Radon inspectors near me: where the lists come from

EPA's Home Buyer's and Seller's Guide says many states require radon professionals to be licensed, certified or registered, and that most states can provide a list of knowledgeable radon service providers doing business in the state. In states that don't regulate radon services, it says to ask the contractor if they hold a professional proficiency or certification credential. Such programs usually issue a photo ID card showing the qualification and its expiration date.

Radon411 keeps a directory of radon measurement professionals and a list of state radon programs. Either way, confirm the credential with the body that issued it; EPA says the tester's ID number should be noted in the test report.

Do home inspectors check for radon?

Some do. EPA's Home Buyer's and Seller's Guide says you can hire a qualified radon tester, "very often a home inspector," who will use a radon device suitable to your situation. The radon test is its own measurement with its own checklist, so ask for it by name when you book, and ask the inspector which radon credential they hold.

Some states may require a signed waiver in that case, and EPA says the testing should then follow its Radon Testing Checklist. The professional directory lists measurement and mitigation separately.

EPA's Radon Testing Checklist sets out what happens before, during and after a test. The occupants' cooperation is part of the result, so know the sequence.

1. 1

   Brief the occupants

   EPA says to tell the occupants why proper testing conditions matter and give them written instructions.

2. 2

   Close the house at least 12 hours ahead

   For a short-term test ranging from 2 to 4 days, EPA says closed-house conditions should be kept for at least 12 hours before the test begins and during the entire test period. For a test of 4 to 7 days, EPA recommends that closed-house conditions be maintained.

3. 3

   Place the device on the lowest level that could be used regularly

   EPA recommends the lowest level of the home that could be used regularly, whether it is finished or unfinished. It sits at least 20 inches above the floor, away from drafts, high heat, high humidity and exterior walls, and not in a closet, stairway, hallway, crawl space, kitchen or bathroom.

4. 4

   Run it for at least 48 hours

   EPA says to run the test for a minimum of 48 hours; some devices need longer, such as a 7-day charcoal canister.

5. 5

   Keep conditions normal and steady

   Run heating and cooling normally, using only air conditioners that recirculate indoor air for tests under a week. Do not disturb the device. A radon-reduction system, if present, must run for the whole test.

6. 6

   Record, return and report

   Start and stop times and the location are recorded and the device goes promptly to the laboratory. EPA says results take a few days or weeks.

What closed-house conditions mean

A radon-reduction fan, or a small exhaust fan run briefly, may operate. EPA also says not to run tests of less than four days during severe storms or high winds.

Both exist because radon levels tend to vary from day to day and season to season, as EPA puts it; WHO adds that they vary even hour to hour. WHO says short-term tests done in compliance with national protocols can be valuable in time-sensitive situations such as home sales.

Passive or continuous: which is more reliable in a sale?

EPA says some active devices are designed to deter and detect interference, and that although they may cost more, they may ensure a more reliable result. Read more on short-term tests, long-term tests and continuous radon monitors.

EPA's Home Buyer's and Seller's Guide was written for the time-sensitive nature of home sales and the potential for device interference. It recommends three short-term options, any of which is acceptable for deciding whether to fix the home.

EPA's trade-off: simultaneous tests improve precision, while sequential tests better represent the seasonal average.

The radon inspection agreement

If the home has not been tested, EPA suggests contract provisions specifying:

• Where the test will be located.
• Who should conduct the test.
• What type of test to do.
• When to do the test.
• How the seller and the buyer will share the test results and test costs, if necessary.
• When radon mitigation measures will be taken, and who will pay for them.

EPA also mentions a non-interference agreement signed by the seller or occupant, and radon service agreements in some areas that cover both testing and mitigation, if needed, for a one-time fee.

Accepting the seller's earlier test

Before accepting the seller's test, EPA says to find out:

• The results of previous testing.
• Who conducted it: the homeowner, a radon professional or someone else.
• Where in the home it was taken, especially if you may live in a lower level than the test covered.
• What structural changes, alterations or changes to the heating, ventilation and air conditioning system have been made since.

A buyer may ask for a new test if the checklist was not met, the last test is not recent (for example, within two years), or the home was renovated since. Negotiation is covered in radon testing during a home inspection.

EPA says there is a potential for test interference in real estate transactions, and lists ways to prevent or detect it:

• Use a test device that frequently records radon or decay product levels, to detect unusual swings.
• Employ a motion detector to find out whether the device was moved or testing conditions changed.
• Use a proximity detector to reveal the presence of people in the room.
• Record the barometric pressure to identify weather that may have affected the test.
• Record the temperature to help assess whether doors and windows were opened.
• Apply tamper-proof seals to windows to ensure closed-house conditions.
• Have the seller or occupant sign a non-interference agreement.

EPA adds that interference is illegal in some states, and that if the seller or tester cannot confirm every checklist item was completed, you should take another test.

Read this figure as textHide the text version

2 pCi/L

4 pCi/L

00 Bq/m³274 Bq/m³4148 Bq/m³6222 Bq/m³8296 Bq/m³10+370 Bq/m³

• Below 2 pCi/L (below 74 Bq/m³)Below both of EPA's guidance levels.
• 2 to 4 pCi/L (74 Bq/m³ to 148 Bq/m³)EPA recommends considering a fix when the level is between 2 and 4 pCi/L.
• At or above 4 pCi/L (148 Bq/m³ and up)EPA recommends fixing a home when the radon level is 4 pCi/L or higher.

The report gives the result in pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. For context, EPA estimates the average indoor radon level at about 1.3 pCi/L, and says roughly 0.4 pCi/L is normally found in the outside air. Check a number with the radon result interpreter.

Results close to the action level are the hardest to read. EPA's example: if the average of two short-term tests is 4.1 pCi/L, there is about a 50 percent chance that the year-round average is somewhat below, or above, 4 pCi/L. EPA also says any radon exposure carries some risk and that no level of radon is safe, so a result under 4 is not a clean bill of health.

Radon found during a home inspection: what happens next

EPA says that if elevated levels are found during the transaction, the buyer and seller should discuss the timing and costs of radon reduction. It also says that where radon problems have been fixed, home sales have not been blocked.

The fix itself is a job for a qualified mitigation contractor, covered in radon remediation systems and radon mitigation. EPA recommends testing again after the work is done, by an independent, qualified radon tester, to confirm that the level has come down.

Both are legitimate. EPA's Citizen's Guide says there are many kinds of low-cost do-it-yourself radon test kits you can get through the mail and in some hardware stores and other retail outlets, and that if you prefer, or if you are buying or selling a home, you can hire a qualified tester. What changes is who is responsible for the conditions, and who the result is credible to.

A kit is inexpensive: one state radon program says an easy-to-use home test kit can be purchased at hardware or home improvement stores for about $20 to $30. EPA says both short-term and long-term passive devices are generally inexpensive, while active devices that continuously record levels may cost more. See radon test kits.

The report is the product of a radon inspection, and EPA's checklist says what makes it usable. A number on its own is not enough for a buyer, a lender's file or a future mitigator.

One inspection is a snapshot. EPA's guides name the moments that call for another one, whether or not the first result was high.

If a mitigation system is installed, the schedule tightens: EPA's Consumer's Guide says a post-mitigation test should be done within 30 days of system installation, and that it is a good idea to retest at least every two years. That schedule is in living with a radon system.

Radon411 does not quote a price for a professional test. EPA's Citizen's Guide calls testing easy and inexpensive, and EPA says active devices may cost more. The radon testing cost page explains what changes the price.

When a professional radon inspection is worth it

• Buying or selling. EPA's Citizen's Guide says buyers frequently want tests made by someone who is not involved in the home sale.
• When interference is a risk. A qualified tester can use the precautions EPA lists, such as continuous monitors, motion detectors and tamper-proof seals.
• After mitigation. EPA recommends that the test after mitigation work be conducted by an independent, qualified radon tester.
• When you want it done for you. EPA says a qualified tester can recommend a testing approach, analyze the data and provide an independent result.

EPA's Citizen's Guide says you can test your home yourself or hire a qualified radon test company, and either takes only a small amount of time and effort. See radon test kits. Testing is the only way to know the radon level in a specific building.