Radon Disclosure for Rentals: Florida, Maine and Colorado Rules
Which states make landlords warn tenants about radon, test for it or fix it: Florida’s lease notice, Maine’s testing law and Colorado’s signed disclosure.
By Seayora Editorial Team · Published · Facts checked · 4 min read
Short answer: A few states regulate radon in rental housing. Florida requires its statutory radon paragraph on at least one document signed with every lease longer than 45 days. Colorado requires a signed radon disclosure, with a bold warning, the landlord’s known test results and a state brochure, before any lease is signed, and treats a failure as a breach of habitability. Maine requires landlords to have buildings tested, to give tenants the results in writing, and lets either side end the lease on 30 days’ notice if radon reaches 4.0 picocuries per liter.
Key takeaways
- Florida: the statutory “RADON GAS” paragraph on at least one document signed at or before the lease (Fla. Stat. § 404.056(5)).
- Colorado: a signed disclosure with a bold warning, known radon records and the state brochure before the lease is signed (C.R.S. 38-12-803).
- Colorado: from 2026, a tenant may void a lease longer than one year if the disclosure is missing or radon of 4 pCi/L or more is not mitigated within 180 days.
- Maine: landlords must have buildings tested and give tenants written results before they sign or pay a deposit (14 M.R.S. § 6030-D).
- Maine: a test at or above 4.0 pCi/L lets the landlord or tenant end the lease on 30 days’ notice, with the deposit returned.
Do landlords have to tell tenants about radon?
In some states, yes. Radon is an invisible, odorless gas that seeps up from the ground. The states below regulate it in three different ways: a fixed warning in Florida, a signed disclosure in Colorado, and testing plus disclosure in Maine.
| State | What is required | Consequence | Source |
|---|---|---|---|
| Florida | The statutory radon paragraph on at least one document signed at or before the lease; stays of 45 days or less excluded | Statutory notice requirement | Fla. Stat. § 404.056(5) |
| Colorado | A signed disclosure before the lease: bold warning, known tests, records and mitigation, and the state brochure | A breach of habitability; a tenant may void the lease (from 2026, only leases over one year) | C.R.S. 38-12-803, 38-12-503(2.4) |
| Maine | Testing by a registered tester; written results to tenants before signing or paying a deposit, and within 30 days of new results | A breach of the warranty of habitability; at 4.0 pCi/L or more either side may end the lease on 30 days’ notice | 14 M.R.S. § 6030-D |
What does Florida require?
Notification “shall be provided on at least one document, form, or application executed at the time of, or prior to, contract for sale and purchase of any building or execution of a rental agreement for any building,” in these words: “RADON GAS: Radon is a naturally occurring radioactive gas that, when it has accumulated in a building in sufficient quantities, may present health risks to persons who are exposed to it over time. Levels of radon that exceed federal and state guidelines have been found in buildings in Florida. Additional information regarding radon and radon testing may be obtained from your county health department.” Residential transient occupancies of 45 days or less are excluded (Fla. Stat. § 404.056).
What does Colorado require?
Since August 7, 2023, “before signing a lease agreement for residential real property, the landlord shall disclose and provide in writing to the tenant” a bold-faced warning in substantially the statutory form, which begins “THE COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT STRONGLY RECOMMENDS THAT ALL TENANTS HAVE AN INDOOR RADON TEST PERFORMED BEFORE LEASING RESIDENTIAL REAL PROPERTY”; whether radon tests have been done, the most current records and reports, any radon detected or mitigation performed, and details of any mitigation system; and the state health department’s current radon brochure. The tenant signs to acknowledge receipt (Senate Bill 23-206, as signed).
A landlord who fails to comply breaches the warranty of habitability. A tenant may void the lease and move out if the landlord did not give the disclosure or did not “make a reasonable effort to mitigate radon within one hundred eighty days after being notified that a radon measurement professional has determined the air concentration of radon is four picocuries per liter or more”; on or after January 1, 2026, that right does not apply to a lease of one year or less (Colorado General Assembly, SB23-206).
What does Maine require?
A landlord must have the air of a residential building tested for radon, by a tester registered with the state, and, unless a mitigation system is installed, again every 10 years when a tenant asks; a building that first opened after March 1, 2014 must be tested within 12 months of first occupancy. Within 30 days of receiving results, and before a new tenant signs a lease or pays a deposit, the landlord gives written notice on the state’s form of the date and results of the latest test, whether mitigation was done, the tenant’s right to test, and the risks. Failing to give the notice, or falsifying a test, is a breach of the implied warranty of habitability. If a test shows 4.0 picocuries per liter or more, “either the landlord or the tenant may terminate the lease or tenancy at will with a minimum of 30 days’ notice,” and the landlord may not keep the deposit for that termination. Short-term rentals of 100 days or less with no renewal are excluded (14 M.R.S. § 6030-D).
What should a landlord do?
- Find out whether your state has a radon rule for leases, and use its exact wording or form.
- Collect every radon test, report and mitigation record you have for each building.
- Attach the disclosure to the lease and get the tenant’s signed acknowledgment where required.
- If a test shows 4 pCi/L or more, hire a mitigation professional promptly and keep the records.
Frequently asked questions
Do landlords have to test for radon?
In Maine, yes: landlords must have buildings tested by a registered tester and share the results. Florida and Colorado require disclosure rather than testing.
What radon level lets a tenant end a lease?
In Maine, a test at or above 4.0 picocuries per liter lets either side end the lease on 30 days’ notice. In Colorado, a tenant may void a lease over one year if radon at 4 pCi/L or more is not mitigated within 180 days of the landlord being notified.
What must a Florida lease say about radon?
It must carry Florida’s statutory “RADON GAS” paragraph on at least one document signed at or before the lease, word for word.
Sources
- Florida Statutes § 404.056 (subsection (5), Notification on real estate documents), The Florida Legislature
- Senate Bill 23-206, Disclose Radon Information Residential Property (as signed), Colorado General Assembly
- SB23-206 bill summary, Colorado General Assembly
- 14 M.R.S. § 6030-D, Radon testing, Maine Legislature
How Seayora helps
Digital lease signing: Attach a radon disclosure to the lease as an addendum so the tenant’s signed acknowledgment is part of the executed lease.
This article is general information, not legal advice. Landlord-tenant law varies by state and city and changes often, so check the current rule for your property and talk to an attorney before acting on a dispute.
How we write and check these guides: editorial standards.
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