EPA radon potential
Zone 3Predicted average indoor radon levels below 2 pCi/L. EPA still cautions that homes in all three zones can have elevated radon. [9]
01 / QUICK READ
Shelby County’s low-risk label is not a substitute for a test.
Radon-resistant new construction is optional across the jurisdictions verified here.
Memphis and unincorporated Shelby County use the 2021 IRC, but their joint ordinance adopts no IRC appendices. Bartlett and Collierville likewise leave out the radon appendix for their code editions. [1] [6] [7]
Bottom line
Zone 3 means lower predicted countywide potential—not zero risk and not proof about a particular address.
Zone 3 means lower predicted countywide potential—not zero risk and not proof about a particular address.
Zone 3EPA low-potential designation; predicted average indoor levels below 2 pCi/L. [9]
OptionalRadon-resistant construction is not mandated in Memphis, unincorporated Shelby County, Bartlett, or Collierville.
~6NRPP listings within roughly 20 miles of the Memphis ZIP searched; only one credential was individually verified. [11]
0NRSB measurement specialists or technicians found within 25 miles of 38103. [13]
02 / RISK & DATA
The public signal is low—but the sample is thin.
EPA’s map and Tennessee’s dashboard point in the same broad direction. Neither can tell you what is happening inside a specific home.
VALUES WITHHELD
Dashboard tooltips did not render reliably.
No validated county statistic
On a second load, the Tennessee dashboard showed a median of 0.9 pCi/L and a maximum of 1.9 pCi/L for Shelby County, but fields were incomplete and inconsistent across loads. The average never rendered. Those numbers are treated as suspect rather than presented here as verified county figures. [10]
What the test-count fragments suggest
After Shelby County was selected, incomplete chart fragments mentioned 42 pre-mitigation tests in 2022 and 9 in 2023, plus a very small post-mitigation view. These counts are not published as firm totals. Even taken at face value, tens of tests are not representative of a county with roughly 920,000 residents.
03 / BUILDING CODES
No verified jurisdiction here makes the radon appendix mandatory.
The appendix letter changes by code edition: Appendix F in the 2018 IRC, Appendix AF in the 2021 IRC, and Appendix BE in the 2024 IRC. [5]
NOT ADOPTED
Memphis + unincorporated Shelby County
2021 IRC with local amendments. The joint ordinance took effect April 1, 2025 and contains 61 local amendments, but no appendix adoption list. Under IRC §R102.5, appendices are not mandatory unless the adopting ordinance specifically references them. Appendix AF is therefore optional. [1] [5]
NOT ADOPTED
Bartlett
Bartlett uses the 2018 IRC. Its adopted appendices are A, B, C, D, G, J, M and N. Appendix F—the radon appendix in that edition—is absent, so radon-resistant construction is not mandatory. [6]
NOT ADOPTED
Collierville
The published code adopts the 2018 IRC through Ordinance 2020-06, passed September 14, 2020. No appendix adoption list or radon provision appears, so Appendix F is not mandatory. [7]
OPEN QUESTION
Germantown
A current primary-source adoption section was not found. Indirect evidence suggests Germantown tracks the 2021 Memphis/Shelby County technical codes, but its IRC edition and appendix list remain unverified.
No extra local radon rule was found.
Research found no Shelby County or Memphis radon-specific mandate for public buildings, schools, or real-estate transactions. State law encourages—not requires—school indoor-air programs that may include radon testing. [14]
How do I find a certified radon professional in Shelby County?
Tennessee doesn't license radon testers or mitigators, so national certification is the best way to check qualifications. The Tennessee Radon Program points residents to two directories: search them by ZIP code and widen the radius if nothing is listed nearby.
We don't recommend or rank companies. Before you hire, check the certification number in the directory yourself and ask for a follow-up test after any system is installed. Questions to ask a radon professional.
04 / HOMEBUYERS
Put the test inside the due-diligence window.
Tennessee does not require a radon test or a standalone radon disclosure in a residential sale. The standard form advises buyers to use appropriate inspection contingencies, including radon.
New does not automatically mean radon-ready.
Because the radon appendix is not adopted in Memphis, unincorporated Shelby County, Bartlett, or Collierville, a buyer should not assume a new home includes passive radon-control features. Ask the builder what was installed, then test after construction.
A written warranty can exempt new construction from Tennessee’s general disclosure requirement, making direct questions and independent testing especially important.
Practical transaction plan
- Write radon into the inspection or due-diligence plan.
- Use a 48-hour-or-longer test under closed-house conditions.
- For new construction, ask about voluntary passive radon features.
- If a result is elevated, consult a certified mitigation professional and retest after work.
05 / TESTING RESOURCES
Start with a free Tennessee test kit.
The state program offers free kits for homeowners and technical information for schools, real-estate professionals, contractors, code officials, and inspectors.
TDEC Radon Program
Request a free home test kit and read Tennessee-specific guidance from the Office of Sustainable Practices.
Open the state radon program →06 / FAQ
Questions Shelby County homeowners ask
Is Shelby County in a high-radon zone?
No. EPA mapping places Shelby County in Zone 3, the low-potential category with predicted average indoor levels below 2 pCi/L. That is not a guarantee for any individual home; testing is still the only way to know a home’s level.
Does Memphis require radon-resistant new construction?
No. The 2021 joint residential ordinance for Memphis and unincorporated Shelby County does not adopt any IRC appendix. Appendix AF—the radon appendix for that edition—is therefore optional rather than mandatory.
Why are no Shelby County dashboard numbers shown as validated statistics?
The Tennessee dashboard rendered 0.9 pCi/L as a median and 1.9 pCi/L as a maximum on one load, but the tooltip was incomplete and inconsistent. The average never appeared. This page withholds those figures as validated statistics rather than overstate uncertain data.
Are Bartlett and Collierville radon-ready by code?
Not by the published adoptions reviewed here. Bartlett’s 2018 IRC appendix list excludes Appendix F. Collierville’s published 2018 adoption names no radon provision or appendix adoption list. Voluntary features may still be installed, so ask the builder and test.
Where can I get a test kit?
TDEC’s statewide Radon Program offers free test kits for Tennessee homeowners. You can also use the NRPP and NRSB directories to look for credentialed professionals.
07 / SOURCES
Primary documents, public data & directories
- Shelby County joint residential ordinance — 2021 IRC amendments, effective April 1, 2025.
- Memphis/Shelby County joint IBC ordinance — appendix-adoption practice.
- Memphis City Council agenda, October 5, 2021 — Ordinance No. 5801.
- Shelby County Commission agenda, November 1, 2021.
- 2021 IRC Appendix AF: Radon Control Methods.
- Bartlett 2018 IRC amendments — adopted appendix list.
- Collierville §150.070 — 2018 IRC adoption and amendments.
- EPA Map of Radon Zones: Tennessee — Shelby County Zone 3.
- EPA Map of Radon Zones — zone definitions and limitations.
- Tennessee Radon Testing dashboard — live checks on October 16, 2026.
- NRPP professional search near 38103 — October 16, 2026.
- NRPP profile: Phil McDonnell — certification details.
- NRSB professional search — 25-mile measurement searches.
- Tennessee School Health Laws — TCA §49-2-121.
- Tennessee Realtors disclosure form — radon inspection-contingency advisory.
- Upchurch Inspection — Memphis-area testing view.
- TDEC Radon Program — free test kits and statewide resources.
Method note. This page separates confirmed ordinance findings from inference and open questions. Suspect dashboard values and incomplete test-count fragments are disclosed but not promoted as validated county statistics. Directory counts are snapshots, not a census.