Are landlords required to test for radon in rentals?

Last updated 2026-07-25

Are landlords required to test for radon?

Not under federal law. The Environmental Protection Agency treats radon testing in rentals as a recommendation, not a mandate, and there's no federal statute requiring landlords to test units for radon gas ^[1]. That said, "not required federally" doesn't mean "not required, period." A handful of states have their own radon testing or disclosure laws that apply to rental housing, and some cities layer additional requirements on top through their rental licensing ordinances. Whether you actually have to test depends entirely on where your property sits. Even where testing isn't legally required, EPA's position is blunt: "Radon is the second leading cause of lung cancer in the United States, after smoking" ^[2], and testing is the only way to know if a unit has a problem. Roughly 1 in 15 homes nationally is estimated to have radon levels at or above the action level of 4 picocuries per liter (pCi/L), per EPA's national radon guidance ^[2]. That estimate varies wildly by region and even block to block, which is part of why blanket rules are hard to write. If you manage property in a city with a rental license or inspection program, check your city's checklist directly. Some inspection programs ask about basement moisture or ventilation issues that correlate with radon risk, even if they don't name radon specifically.

Which states require radon testing or disclosure for rental properties?

State law is where most real radon obligations for landlords actually live. Here's a rough sketch of the landscape, but you should confirm current requirements with your state's environmental or health agency before treating any of this as final. Illinois requires that landlords give tenants a radon disclosure document at or before lease signing under the Illinois Radon Awareness Act, and post it in a common area if there's no individual lease per unit ^[3]. The disclosure has to include a specific pamphlet developed by the Illinois Emergency Management Agency and, if the landlord has actual knowledge of a radon test result, that result gets disclosed too. New Jersey doesn't mandate rental testing statewide, but the state Department of Environmental Protection maintains detailed radon program guidance and requires radon testing during real estate transactions in certain high-radon zones, which indirectly shapes what landlords who buy or refinance properties end up knowing ^[4]. Florida requires a specific radon gas disclosure statement in most residential leases and real estate contracts under Florida Statutes section 404.056(5), which reads in part that every contract for sale, and every rental agreement, must contain a specific radon notification ^[2]. A few other states (including New York in certain program contexts, and various New England states with historically high radon zones) have testing or disclosure requirements tied to specific situations, like school buildings, day cares, or state-assisted housing, rather than a blanket rule for all private rentals. This is a patchwork, not a system, and it changes. Confirm with your state's environmental agency or your city rental licensing office before you assume you're exempt. If you're building out a compliance file for a city rental license application, it's worth keeping your radon disclosure (if your state requires one) in the same packet as your lead paint disclosure and any other required notices. Landlords managing tenants rights obligations across multiple jurisdictions often find it easier to over-disclose than under-disclose.

Does EPA recommend radon testing even where it isn't required?

Yes, unambiguously. EPA's guidance states that all homes should be tested for radon regardless of geographic location or foundation type, and that includes rental units below the third floor ^[1]. EPA's specific recommendation for property owners: test using a short-term test kit (2 to 90 days) or long-term kit (more than 90 days), and if results come back at or above 4 pCi/L, take action to mitigate ^[2]. EPA has stated its own goal is for indoor radon levels to be no higher than outdoor levels, which typically average around 0.4 pCi/L, but 4 pCi/L is the actionable threshold they use for practical guidance ^[2]. A basic test kit runs somewhere in the $15 to $30 range at most hardware stores, and many state radon programs distribute free or reduced-cost kits to residents. Professional radon testing by a certified measurement technician typically costs more, often in the $100 to $200 range depending on your market, and mitigation systems (sub-slab depressurization is the most common fix) usually run between roughly $800 and $2,500 per unit ^[2]. For a landlord with 1 to 10 units, testing every unit once is a small, one-time cost relative to the liability exposure if a tenant later claims you knew about a radon problem and didn't disclose it. I'd test even where it's not required. It's cheap insurance against a much bigger headache.

What happens if a landlord doesn't test or disclose radon results?

Consequences depend entirely on your state and city. In states with a mandatory disclosure law like Illinois or Florida, failing to provide the required radon notice can expose a landlord to fair housing or consumer protection claims, and in some cases voids certain lease protections the landlord would otherwise have ^{[3] [2]}. In cities without any radon-specific rule, the bigger risk isn't a fine, it's a lawsuit. If a tenant develops a radon-related health issue (or claims one) and can show the landlord knew about elevated levels and didn't disclose them, that's a negligence claim waiting to happen. Radon is odorless and invisible, so tenants generally have no way to know about a problem unless you tell them or they test on their own. Cities that run their own rental licensing and inspection programs sometimes flag radon indirectly, through basement ventilation requirements or general habitability standards, even if the word "radon" never appears in the ordinance. If your city sends an inspection notice, read the full checklist rather than assuming radon isn't covered just because it's not named. If you got an ordinance notice or a violation letter referencing environmental hazards and you're not sure whether radon applies, that's exactly the kind of gap a landlord should close proactively rather than wait to find out at inspection.

What can a landlord look at during an inspection?

A landlord conducting a routine unit inspection can generally check smoke detectors and carbon monoxide detectors, look for visible plumbing or electrical hazards, check for mold or moisture damage, verify working locks and windows, and confirm the unit matches habitability standards under your state's landlord-tenant code. What a landlord typically cannot do is search through a tenant's personal belongings, closets, drawers, or private files unrelated to the inspection's purpose. Most states require landlords to give tenants advance notice before entering for a non-emergency inspection, commonly 24 hours, though the exact number varies by state statute. The inspection should be limited to areas relevant to habitability and safety, not a general walkthrough of the tenant's possessions. Radon testing itself usually just requires placing a small test kit in the lowest lived-in level of the unit for the test period, then retrieving it. It's minimally invasive and doesn't require a full walkthrough, which is one more reason there's little excuse not to do it even where it's optional.

Who is responsible for rental property walkthrough inspections in California?

In California, the landlord is generally responsible for conducting move-in and move-out walkthrough inspections, and state law gives tenants specific rights around that process. Under California Civil Code section 1950.5, landlords must, upon request, do an initial inspection before the tenant moves out (an "initial inspection") to identify deficiencies that could lead to deductions from the security deposit, and give the tenant an itemized statement of anticipated repairs ^[5]. The landlord has to give the tenant at least 48 hours' written notice before that initial move-out inspection unless the tenant waives that notice ^[5]. After the actual move-out, the landlord has 21 days to return the security deposit along with an itemized statement of any deductions ^[5]. Some California cities layer their own rental inspection programs on top of this, particularly cities with rent stabilization or proactive rental inspection ordinances (San Francisco and Los Angeles both have systematic inspection programs tied to habitability enforcement). Those inspections are usually conducted by city inspectors, not the landlord, and are separate from the security deposit walkthrough. Check with your specific city's rental housing or code enforcement department to see if a city-run inspection applies to your property in addition to the standard move-in/move-out process.

What can't a landlord do in Ohio?

Ohio landlord-tenant law, found in Ohio Revised Code Chapter 5321, sets out specific things a landlord cannot do. A landlord cannot shut off utilities, change locks, or remove a tenant's belongings to force them out without going through the formal eviction process in court, sometimes called "self-help eviction," and Ohio courts treat this as illegal regardless of how far behind a tenant is on rent . A landlord in Ohio also cannot retaliate against a tenant for exercising a legal right, such as reporting a code violation or joining a tenant union, under ORC 5321.02 . Ohio law requires landlords to give reasonable notice, generally interpreted as 24 hours, before entering a unit for a non-emergency purpose, per ORC 5321.04 . Ohio landlords also can't ignore their duty to maintain the property in a habitable condition. ORC 5321.04 requires landlords to keep the premises in compliance with building, housing, and health codes, keep common areas safe, and maintain working plumbing, heating, and hot water . None of this is radon-specific, Ohio has no statewide radon disclosure mandate as of this writing, but it does mean an Ohio landlord who ignores a known radon problem could still run into habitability arguments under the general fitness standard.

How much notice does a landlord have to give before entering a unit?

Most states require 24 hours' notice for a non-emergency entry, though the specific number and the form of notice (written vs. verbal, and how it must be delivered) varies by state. Some states, like California, set a presumptive standard of 24 hours' notice under Civil Code 1954, but allow different notice for specific circumstances like the move-out inspection, which requires 48 hours ^[5]. Emergencies (fire, flood, a burst pipe) are the standard exception almost everywhere, allowing a landlord to enter without advance notice when there's an immediate threat to health or safety. Radon testing doesn't count as an emergency. So if you're placing a test kit as a routine measure rather than during an already-scheduled inspection, give standard notice under your state's rule. If you're not sure what your state requires, check your state's landlord-tenant statute directly rather than relying on a generic rule of thumb, since a few states allow shorter or longer windows depending on the purpose of entry.

What is landlording, and what does a landlord actually do?

Landlording is the practical work of owning and managing rental property: finding and screening tenants, handling leases, collecting rent, maintaining the unit, responding to repair requests, and staying compliant with local, state, and sometimes city-specific rental laws. A landlord is the legal owner (or authorized manager) of a rental property who rents that property to a tenant in exchange for payment, taking on both the income and the legal responsibilities that come with it. The responsibilities go well past collecting a check. A landlord in most states has an implied or statutory duty to maintain "habitability," meaning the unit has working plumbing, heat, electricity, and structural safety. Layer on top of that any city-specific rental licensing, registration, or inspection requirements, and landlording starts to look a lot like running a small compliance-heavy business, even for someone with a single unit. Many first-time landlords underestimate how much of the job is paperwork and deadlines rather than fixing faucets. If your city sent you a rental license renewal notice or an inspection date, that's landlording too, not a side task.

How do you become a landlord, step by step?

Becoming a landlord generally means acquiring a rental property (by purchase or converting a property you already own), understanding your state's landlord-tenant law, registering with your city if required, screening and selecting a tenant, and executing a legally compliant lease. A reasonable order of operations: confirm the property meets local zoning and rental licensing rules before you list it (many cities require a rental license or registration before you can legally lease a unit, and some require a pre-rental inspection first). Get familiar with your state's security deposit, notice, and habitability rules. Screen tenants consistently and in compliance with fair housing law (the federal Fair Housing Act, 42 U.S.C. 3601 et seq., prohibits discrimination based on race, color, religion, sex, national origin, familial status, or disability). Draft or use a lease that matches your state's required disclosures, which may include radon, lead paint, mold, or bed bug history depending on your state. Then keep records: inspection dates, repair requests, entry notices, and rent payments. If your city requires a rental license, that step often needs to happen before you can legally advertise or lease the unit, not after. Missing that step is one of the most common first-year mistakes new landlords make, and it's also one of the more expensive ones to fix retroactively once a city catches it. This is exactly the kind of gap our $79 City Rental License & Inspection Prep Packet is built to close: it walks you through what most city programs expect before you get a violation notice.

Why do landlords require renters insurance?

Landlords require renters insurance mainly to shift liability for a tenant's personal property and personal liability away from the landlord's own policy. A standard landlord insurance policy covers the building and the landlord's liability, but it typically does not cover a tenant's furniture, electronics, or clothing if there's a fire, burst pipe, or theft. Requiring renters insurance also protects the landlord if a tenant's guest is injured in the unit, or if the tenant accidentally causes damage (a kitchen fire, an overflowing tub) that affects other units in a multifamily building. Without renters insurance, that liability and cost exposure can land back on the landlord's policy, raising the landlord's own premiums or leaving a gap nobody covers. It's common, and generally legal in most states, for a lease to require proof of renters insurance as a condition of tenancy, similar to requiring a security deposit. Check your state's law on what a landlord can and can't require as a lease condition before adding this, since a few jurisdictions have specific rules about how this has to be handled.

What rights do tenants have without a signed lease?

A tenant without a signed written lease still has legal rights, generally the same habitability, notice, and eviction protections as a tenant with a lease, because most of those rights come from state statute, not from the lease document itself. What's usually missing without a written lease is clarity on rent amount, due date, and lease term, which can create disputes. In most states, a tenant paying rent regularly without a written lease is treated as a month-to-month tenant under state law, meaning either party generally has to give the statutory notice period (commonly 30 days, though this varies by state and by how long the tenancy has run) to end the tenancy. A landlord still cannot evict a tenant without a lease through self-help methods like changing locks or removing belongings. The formal eviction process through the courts still applies. Tenants without a lease are also still covered by fair housing law and, in most states, by implied habitability standards requiring the landlord to maintain safe and livable conditions regardless of whether anything was signed. If you're renting without a written lease, both sides should assume the relevant state statute fills the gaps, and it's worth putting terms in writing anyway to avoid disputes later. Landlords navigating renters rights questions with an unwritten agreement should treat state landlord-tenant code as the default contract.

Frequently asked questions

Is radon testing legally required for rental properties?

Not under federal law. Some states, including Illinois and Florida, require radon disclosure or testing-related notices in leases. Most states have no such requirement. Check with your state's environmental or health agency, since the list of states with radon rules changes over time.

What radon level is considered dangerous in a rental unit?

EPA recommends taking action to reduce radon levels at or above 4 picocuries per liter (pCi/L). EPA's stated goal is to bring indoor levels down to outdoor average levels, roughly 0.4 pCi/L, but 4 pCi/L is the actionable threshold used in most guidance and state programs.

How much does a radon test cost for a rental unit?

A basic short-term test kit typically costs $15 to $30 at hardware stores. Professional testing by a certified technician usually runs $100 to $200 depending on your market. Many state radon programs also offer free or discounted kits to residents.

How much does radon mitigation cost if a unit tests high?

EPA's consumer guidance puts typical mitigation system costs, most commonly sub-slab depressurization, at roughly $800 to $2,500 per unit, though costs vary by foundation type, unit size, and local contractor rates.

How to become a landlord if you've never rented a property before?

Confirm zoning and any city rental licensing rules apply to your property, learn your state's landlord-tenant law (security deposits, notice periods, habitability standards), screen tenants in compliance with fair housing law, and use a lease matching your state's required disclosures. Register with your city before advertising if a rental license is required.

Who is responsible for the rental property walkthrough inspection in California?

The landlord conducts move-in and move-out walkthroughs. Under California Civil Code 1950.5, tenants can request an initial move-out inspection with at least 48 hours' written notice, and the landlord must return the security deposit with an itemized statement within 21 days after move-out.

What is landlording?

Landlording is the day-to-day work of owning and managing rental property: screening tenants, collecting rent, handling repairs, maintaining habitability, and complying with local, state, and city rental laws. It's part property management and part ongoing legal compliance.

What is a landlord, legally speaking?

A landlord is the legal owner or authorized manager of a rental property who leases it to a tenant in exchange for rent. Legally, this role comes with statutory duties, most notably a duty to maintain habitable conditions and to follow state and local rental laws.

What rights does a tenant have without a signed lease?

A tenant without a written lease generally keeps the same habitability, notice, and eviction protections as one with a lease, since those come from state statute. Without a written term, most states treat the tenancy as month-to-month, requiring standard statutory notice (often 30 days) to end it.

Why do landlords require renters insurance?

Renters insurance covers a tenant's personal belongings and personal liability, which a landlord's own policy usually doesn't cover. Requiring it shifts that risk away from the landlord and reduces disputes over who pays for tenant property damage or injury claims.

How much notice does a landlord have to give before entering a unit?

Most states require at least 24 hours' notice for non-emergency entry, though the exact rule varies. California requires 24 hours generally under Civil Code 1954, but 48 hours for a requested move-out inspection under Civil Code 1950.5. Emergencies are typically exempt from notice requirements.

What can a landlord look at during a rental inspection?

A landlord can generally check smoke and carbon monoxide detectors, plumbing, electrical safety, mold or moisture, and general habitability conditions. A landlord generally cannot search personal belongings, drawers, or areas unrelated to safety and maintenance.

What can't a landlord do in Ohio?

Under Ohio Revised Code Chapter 5321, a landlord cannot use self-help eviction (shutting off utilities, changing locks, removing belongings), cannot retaliate against a tenant for exercising legal rights, and must give reasonable notice, generally 24 hours, before non-emergency entry.

Does every state require radon disclosure in leases?

No. Only a subset of states currently have radon disclosure or testing requirements specific to rentals, Illinois and Florida among them. Most states have no statewide radon disclosure mandate for residential leases, though this can change, so confirm current rules with your state agency.

Sources

1. EPA, A Citizen's Guide to Radon: EPA recommends testing all homes for radon regardless of location, with no federal mandate for rental testing
2. EPA, Health Risk of Radon: Radon is the second leading cause of lung cancer in the US after smoking; roughly 1 in 15 homes has elevated radon; EPA action level is 4 pCi/L; typical mitigation costs run roughly $800 to $2,500 per unit
3. New Jersey Department of Environmental Protection, Radon Program: New Jersey maintains state radon testing and disclosure guidance tied to real estate transactions
4. Florida Statutes Section 404.056: Florida law requires a specific radon gas disclosure statement in residential leases and real estate contracts
5. California Civil Code Section 1950.5: California requires 48 hours' notice for a requested move-out inspection and 21 days to return a security deposit with an itemized statement
6. Ohio Revised Code Chapter 5321: Ohio law prohibits self-help eviction, prohibits retaliation, and requires reasonable notice before landlord entry