Radon in a home sale
The radon test during a home inspection
Standard home inspections leave radon out; the radon test is a separate service, often sold by the same inspector. In Illinois 124 of 306 radon measurement professionals are also licensed home inspectors. Whether your inspector may run the test depends on the state.
Who may run the radon test, state by state
| State | Radon credential for the tester | Is radon in the standard inspection? |
|---|---|---|
| Illinois | A home inspector who runs radon tests for clients needs an IEMA-OHS measurement license. The only retail exemption excludes sellers that also serve the client through home inspection or real estate representation. source, read October 15, 2026 | The contract may state the inspector is not required to perform engineering or environmental services. The standards of practice do not list radon testing among the inspected systems. source, read October 15, 2026Illinois home inspector rules |
| Pennsylvania | Anyone who places and retrieves a radon test device for someone else, such as a home inspector in a sale, must hold DEP testing certification. source, read October 15, 2026 | Checks limited to items such as air and water quality or environmental hazards are not home inspections under the law, so a radon test alone is not one. source, read October 15, 2026Pennsylvania home inspector rules |
| Colorado | Since July 1, 2022, anyone who performs radon measurement or radon mitigation in Colorado must meet the state qualifications and hold a license from the director of DORA's Division of Professions and Occupations. source, read October 15, 2026 | CDPHE encourages buyers to have a licensed radon measurement professional test during the inspection period, and to work with the seller on a mitigation system if levels are elevated. source, read October 15, 2026 |
| Connecticut | To be listed by DPH as a radon measurement professional, a tester takes a two day course and becomes certified by NRPP or NRSB. source, read October 15, 2026 | A standard Connecticut inspection does not have to check for radon, mold, asbestos, lead paint or other environmental hazards. source, read October 15, 2026 |
| Delaware | Delaware does not certify radon testers or mitigators; its Division of Public Health keeps only a voluntary company list. source, read October 15, 2026 | A standard Delaware inspection does not have to find environmental hazards, including radioactive substances such as radon, or contaminants in air, water or soil. source, read October 15, 2026 |
How a sale test is run
- Three short-term sale options
- For a home sale, EPA's buyer and seller guide accepts any of three short-term testing options to decide whether to fix.U.S. Environmental Protection Agency, read October 15, 2026
- Sale test placement
- In a sale, the test device goes in the lowest level that could be used regularly, finished or not.U.S. Environmental Protection Agency, read October 15, 2026
- Buyer may ask for retest
- A buyer may ask for a new test, for example when the seller's test is more than about two years old.U.S. Environmental Protection Agency, read October 15, 2026
- Contract: who pays mitigation
- EPA suggests buyers consider contract terms for the radon test, including when any mitigation happens and who pays for it.U.S. Environmental Protection Agency, read October 15, 2026
- No digital monitors in sales
- A national advisory posted by DEP says consumer digital radon monitors should not be used for real estate tests.Conference of Radiation Control Program Directors (posted by Pennsylvania DEP), read October 15, 2026
- Real estate test safeguards
- A radon test for a real estate deal must use anti-tampering procedures.PA Environmental Quality Board, 2018 final rule text (posted by DEP), read October 15, 2026
Who buyers end up hiring
- Testers are often inspectors
- EPA notes that the qualified radon tester a buyer hires is very often a home inspector.U.S. Environmental Protection Agency, read October 15, 2026
Got the number? Read it on EPA's scale. Need a fix before closing? Published mitigation prices.
Sources
- U.S. Environmental Protection Agency, read October 15, 2026.
- U.S. Environmental Protection Agency, read October 15, 2026.
- Illinois General Assembly (Illinois Compiled Statutes), read October 15, 2026.
- Illinois General Assembly, Joint Committee on Administrative Rules (Illinois Administrative Code), read October 15, 2026.
- Pennsylvania Department of Environmental Protection, read October 15, 2026.
- Pennsylvania General Assembly, read October 15, 2026.
- Colorado General Assembly (Session Laws 2021, ch. 398, HB21-1195), read October 15, 2026.
- Colorado Department of Public Health and Environment, read October 15, 2026.
- Connecticut Department of Public Health, Radon Program, read October 15, 2026.
- Connecticut Department of Consumer Protection (Regulations of Connecticut State Agencies 20-491), read October 15, 2026.
- Delaware Division of Public Health, read October 15, 2026.
- Delaware Administrative Code (state archive), read October 15, 2026.
- Conference of Radiation Control Program Directors (posted by Pennsylvania DEP), read October 15, 2026.
- PA Environmental Quality Board, 2018 final rule text (posted by DEP), read October 15, 2026.
- Illinois overlap: IEMA-OHS active licensee list and IDFPR home inspector licenses (data.illinois.gov), first and last name match, 2026-10-15.