Radon Laws in Tennessee: Testing, Disclosure & Mitigation Rules

The Short Answer

Tennessee regulates radon primarily through residential real estate seller disclosures and public education coordinated by state environmental agencies. Under the Tennessee Residential Property Condition Disclosure Act (Tennessee Code Annotated § 66-5-201 et seq.), residential property sellers must provide a standardized disclosure statement disclosing known environmental hazards, including historical radon tests and mitigation systems. Tennessee does not operate a direct state licensing board for radon testers or mitigators, officially referring property owners to national NRPP and NRSB registries. Geologically, extensive karst limestone formations across Middle and East Tennessee create elevated radon potential.

Testing Requirements

Indoor radon testing is voluntary for private single-family homeowners and residential landlords under Tennessee law; the state does not compel property owners to test existing residential dwellings prior to occupancy or sale. Furthermore, Tennessee statutes do not mandate routine radon testing in public or private K-12 school buildings or commercial child care facilities, though the Tennessee Department of Environment and Conservation (TDEC) and the Tennessee Department of Health strongly encourage voluntary school screening using EPA protocols.

Real-Estate Disclosure

Real estate disclosure is codified under Tennessee Code Annotated (TCA) §§ 66-5-201 through 66-5-210. Under TCA § 66-5-202, sellers of residential real property (1 to 4 dwelling units) must deliver a completed Tennessee Residential Property Condition Disclosure form to prospective purchasers prior to contract acceptance. The form explicitly requires sellers to disclose actual knowledge of environmental hazards affecting the property, specifically including radon gas, past test results, and installed mitigation equipment. While the statute obligates sellers to truthfully report known conditions, it does not mandate pre-closing testing, leaving testing contingencies to purchase negotiations.

Mitigator & Tester Certification

Tennessee has no state licensing requirement for radon measurement technicians or mitigation contractors, per the Tennessee Department of Environment and Conservation, verified November 2026. The state maintains no state-administered radon licensing board or examination. Instead, TDEC officially recommends that homeowners, commercial buyers, and building officials hire professionals who maintain active national certification through the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB). Contractors installing mitigation systems must comply with local municipal building and electrical trade permits.

New Construction

Tennessee does not enforce a statewide mandatory building code requiring passive or active Radon-Resistant New Construction (RRNC) in all new residential buildings. Building code adoption and enforcement operate under local county and municipal jurisdiction. While model codes like the International Residential Code Appendix F contain passive soil-gas ventilation standards, Tennessee has not mandated Appendix F statewide for single-family construction, though several high-risk municipalities and custom builders voluntarily install passive rough-ins during foundation framing.

Radon Zones & the Action Level

According to the EPA Map of Radon Zones, Tennessee exhibits significant geological radon potential driven by underlying karst limestone and shale. Extensive counties across East Tennessee—including Knox (Knoxville), Hamilton (Chattanooga), Anderson, Blount, and Sullivan—and Middle Tennessee—including Davidson (Nashville) and Williamson (Franklin)—are designated as EPA Zone 1 (High Potential), where predicted average indoor screening levels exceed 4.0 pCi/L. Remaining Middle and East Tennessee counties are classified as Zone 2 (Moderate Potential, 2.0 to 4.0 pCi/L), while West Tennessee alluvial plains are classified as Zone 3 (Low Potential, < 2.0 pCi/L). TDEC adopts the federal action level benchmark of 4.0 pCi/L. For county-level geological maps, review our EPA Radon Zone Map guide.

The State’s Radon Program

The state’s official public health and environmental initiative is the Tennessee Department of Environment and Conservation (TDEC) Radon Program, based within the Office of Policy and Sustainable Practices. TDEC provides public education, maintains regional risk statistics, and distributes free or subsidized short-term test kits to Tennessee residents through its online portal. Homeowners and contractors can order test kits and review certified contractor guidance via the official TDEC Radon Program website or by calling the state radon line at 800-232-1139.

Sources & Limits

This regulatory guide is provided for educational and informational purposes only and does not constitute formal legal, building code, or engineering counsel. State statutory disclosure requirements and local building codes are subject to legislative amendment. Property buyers, sellers, landlords, and contractors should verify current rules directly with TDEC or a licensed Tennessee real estate attorney.

Official Sources: Tennessee Code Annotated §§ 66-5-201–66-5-210; Tennessee Department of Environment and Conservation (TDEC); U.S. Environmental Protection Agency (Map of Radon Zones).

To examine how Tennessee’s regulatory framework compares to other states across the nation, consult our master guide to radon regulations across the United States or inspect the EPA Radon Zone Map.