Florida may seem an unlikely high-radon state given its tropical climate and reputation for flat, sandy soil. But parts of Florida — particularly the phosphate-rich central ridge region — have significant radon potential. Florida has enacted one of the more active southern state radon programs, with contractor licensing requirements and specific disclosure obligations. The Florida Department of Health administers the Florida Radon Program and the Building Radon Resistance Program (BRRP) for new construction.
EPA Radon Zone Designation
Florida counties range from Zone 1 in the central phosphate ridge region to Zone 2 and Zone 3 in coastal and southern counties. The highest-radon areas are concentrated in the central Florida phosphate region: Alachua, Columbia, Gilchrist, Hamilton, Hernando, Levy, Madison, Marion, Pasco, Polk, Putnam, Suwannee, and Taylor counties. North-central Florida counties show the state’s highest radon concentrations.
Radon Contractor Licensing in Florida
Florida has a comprehensive radon contractor licensing program. Florida law requires radon contractors to hold a Florida state radon license — the Florida Radon License is issued by the Florida Department of Health and requires passing state examinations, carrying liability insurance, and completing continuing education. Florida additionally requires that radon measurement in real estate transactions be conducted by a Florida-licensed radon measurement business. The Florida DOH maintains a searchable database of licensed radon contractors. Performing radon work without a Florida license is a violation of state law.
Radon Disclosure Requirements in Florida
Florida statute requires that buyers of residential property be provided with the Florida Radon Hazard Notification. Specifically, Florida Statute 404.056(5) requires that all contracts for sale and purchase of buildings include a disclosure statement about radon. The statutory disclosure language must appear in residential real estate contracts. Additionally, sellers who know of elevated radon test results have a duty to disclose this under Florida’s general material defect disclosure requirements.
Radon-Resistant New Construction in Florida
Florida has enacted the Building Radon Resistance Program (BRRP), which encourages RRNC features in new residential construction. The Florida Building Code incorporates provisions for radon-resistant construction in high-radon areas. Given Florida’s unique construction type — many homes are concrete block construction on slab foundations — RRNC implementation requires adaptations from the standard gravel sub-slab approach used in northern climates. The Florida DOH radon program provides technical guidance specific to Florida construction types.
Frequently Asked Questions
Does Florida have high radon levels?
Parts of Florida — particularly the central phosphate ridge region — have significant radon potential. North-central Florida counties overlying phosphate geology can have elevated radon levels comparable to many Zone 1 northern states. Coastal and southern Florida counties generally have lower levels.
Does Florida require radon contractor licensing?
Yes. Florida has a comprehensive radon contractor licensing program. Both measurement and mitigation require Florida state radon licenses, issued by the Florida Department of Health. Verify license status through the Florida DOH radon program before hiring.
Does Florida law require radon disclosure in real estate?
Yes. Florida Statute 404.056(5) requires that all residential real estate contracts include a radon hazard notification. Sellers with known elevated radon results have an additional duty to disclose under Florida’s material defect disclosure requirements.
Florida Phosphate Geology and Radon
North-central Florida’s phosphate mining region is the geological foundation of Florida’s radon risk. Phosphate deposits are naturally high in uranium — when phosphate is present in soil and rock, radon follows. The Florida phosphate belt runs through Hillsborough, Polk, Manatee, Hardee, Desoto, and Sarasota counties in west-central Florida, and through Alachua, Marion, Levy, Gilchrist, and Columbia counties in north-central Florida. Homes built over disturbed phosphate lands — including many in Hillsborough County (Tampa area) and Polk County (Lakeland area) — can have elevated radon even in the absence of a basement, because the phosphate-rich fill material itself can emit radon through slab-on-grade foundations.
Florida RRNC and Slab Construction Specifics
Florida’s Building Radon Resistance Program (BRRP) addresses the unique challenge of Florida’s predominantly slab-on-grade construction. Unlike northern states where basements provide a clear sub-slab entry point, Florida slab homes require specific RRNC techniques including: sub-slab vapor barriers sealed around all penetrations, a passive vent pipe through the slab and interior to above the roofline, and sealing of all slab penetrations. Florida’s warm climate means no stack effect advantage in summer — passive systems in Florida are less effective than in cold climates, making active (fan-powered) mitigation more likely to be needed even with RRNC features installed.
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