How does a home inspector get certified to test for radon?

The National Radon Proficiency Program (NRPP) is a program of the American Association of Radon Scientists and Technologists (AARST), accredited by the ANSI National Accreditation Board. The other national program is the National Radon Safety Board (NRSB). EPA's page on finding a radon professional calls them "the two currently-recognized national radon proficiency programs."

Each has two levels for testing. The higher one oversees the quality control plan. NRPP's lower level places and picks up devices under a professional's supervision. This table compares the two programs as of October 2026:

The sources for the table are NRPP's types of certification, fee update, and renewal page, and NRSB's professional FAQs and renewal page. Course fees come from the training provider and are not part of these figures.

EPA ran its own radon proficiency program until 1998, according to the Virginia Department of Health. The same page names NRSB and NRPP as the bodies that certify radon professionals.

What EPA does is point people to the states. It requires states that take indoor radon grants to list only providers credentialed through a state process or one of the two national programs. Its state radon contacts list gives each state's program, phone number, and website. That is the first call before buying a course.

Some older state rules still name the EPA exam or EPA listing. Rhode Island, West Virginia, and Maine are examples. Their application forms, dated 2020 to 2026, ask for NRPP or NRSB proof instead.

On the health side, EPA's radon health risk page calls radon the second leading cause of lung cancer.

EPA's Home Buyer's and Seller's Guide to Radon (a PDF) says many states require radon professionals to be licensed, certified, or registered. These are the states read for this page, as of October 2026. It is not every state, and rules and fees change, so confirm with the state program before applying.

Two details catch home inspectors. Maine lets owners test their own home only when it is not for sale. Kentucky's exemption for stores that sell test kits does not cover a seller who also does the home inspection. Maine and Pennsylvania have their own pages on this site: Maine and Pennsylvania.

The lower level costs less and takes a shorter course. Under NRPP, it does not stand alone. A field technician works under a certified Measurement Professional, who signs a statement taking responsibility. The professional runs the quality control and registers the devices. NRSB lets its technician run the quality plan only for the technician's own measurement services.

Several states split the levels too. Illinois licenses technicians to work under a professional. Florida says all technicians must be supervised by specialists. Rhode Island requires every radon inspector to own or work for a certified testing business. An inspector who plans to test alone needs the higher level.

EPA's buyer's guide sorts devices into two groups. Passive devices need no power. They include charcoal canisters, alpha-track detectors, charcoal liquid scintillation devices, and electret ion chambers, and they go to a lab for analysis. Active devices, mainly continuous radon monitors, need power and record the level as the test runs.

EPA notes that a monitor's report can show unusual swings in the level during the test. The same guide says every test should run at least 48 hours.

Both national programs require an approved device. NRPP keeps an approved device list, and NRSB requires an NRSB-approved device. Two examples from one maker, with prices as of October 2026:

• Ecosense lists the RadonEye Pro continuous monitor at $779. Its page calls the monitor NRPP and NRSB certified and says it needs calibration every year.
• Ecosense leases the EcoQube Pro monitor at $30 a month per monitor, $35 in New Jersey, plus a $100 activation fee. Annual calibration is part of the lease.

Prices for passive kits vary by lab and were not posted on the vendor pages read for this page.

A certificate is only part of the job. The programs and the states also check that the devices read correctly. These are the duties named in the sources read:

• An NRPP professional with a continuous monitor sends proof of calibration every year and a device performance test from an approved chamber every 2 years.
• NRSB asks for a calibration certificate no older than 12 months for each continuous monitor.
• Florida's rule says a measurement business's quality plan can include instrument calibrations and blank, duplicate, and spiked measurements.
• Pennsylvania runs blind studies and expects results within 25 percent of the reference value.

The sources are NRPP's types of certification, NRSB's certification requirements, the Florida rule, and 25 Pa. Code 240.203. Renewal means more continuing education hours too. If the state has approved a radon course, it might also count toward home inspector license renewal. For more information, see how much continuing education home inspectors need.

In Russ Motyko's view, from more than 3,000 inspections, radon testing is the easiest add-on to start with and to explain. The equipment cost is modest, the training is short, and the time on site is small.

To get from no credential to a first paid test, follow these steps:

1. Call the state radon program, from EPA's state contacts list, and ask which credential it requires.
2. Pick NRPP or NRSB, whichever the state accepts or names.
3. Take an approved initial course at the level you plan to work at.
4. Pass the exam, then apply within a year, since both programs count a score for 1 year.
5. Buy or lease an approved device, and register it with the program.
6. Apply for the national credential, then for the state one if the state has one.

To check that it worked, ask the state program to confirm the credential is on file. For how to price the test once it is offered, see how much a new home inspector should charge. For the other add-ons and what each one takes, see home inspector add-on services that make the most money.