Radon testing requirements for licensed home daycare

Last updated 2026-07-09

Why does radon matter specifically for home daycares?

Radon is a radioactive gas that comes up out of the ground. It seeps from uranium-bearing soil and rock, enters buildings through foundation cracks and gaps around pipes, and builds up indoors. You cannot smell it, see it, or taste it.

The EPA estimates radon causes about 21,000 lung cancer deaths a year in the United States, which makes it the second-leading cause of lung cancer after smoking ^[1]. Children breathe faster than adults. They also spend more hours near the floor, where radon sits thickest. A home daycare where toddlers nap on floor mats in a basement playroom is close to the worst exposure setup you can build.

Licensed home daycares sit where two risks meet. One is residential buildings, which often go untested for years. The other is a group of young children with developing lungs spending six to ten hours a day inside. That mix is why licensing agencies have started treating radon the way they treat smoke detectors. In a growing number of states, testing is no longer optional.

Which states require radon testing for licensed home daycare?

No federal law requires radon testing in childcare. The Child Care and Development Fund (CCDF), which funds subsidized childcare in all 50 states, sets health and safety baselines, but CCDF rules do not name radon testing as a required standard ^[2]. So the rules fall to each state.

As of 2024, roughly 20 to 25 states have some radon requirement or written guidance for licensed childcare, including family home daycares. What that means in practice swings hard from state to state.

State	Requirement level	Who must test	Action threshold
Illinois	Mandatory	All licensed home daycares	4 pCi/L
Iowa	Mandatory	All licensed home and center care	4 pCi/L
Minnesota	Mandatory	All licensed family day care homes	4 pCi/L
New Jersey	Mandatory	All licensed child care centers and home daycares	4 pCi/L
Pennsylvania	Mandatory	Licensed child care homes	4 pCi/L
Ohio	Recommended, not required	All childcare providers	4 pCi/L
Wisconsin	Required for new licenses	Family home daycares at initial licensure	4 pCi/L
Virginia	Required at application	Licensed family day homes	4 pCi/L

This table covers the states with the clearest published rules as of mid-2025. Several others have pending bills or informal guidance that licensing specialists apply inconsistently. If your state is not listed, you are not off the hook. Your licensing agency may still check for radon during a general health and safety sweep. Verify with your own licensing office.

Illinois's Child Care Act requires family homes licensed for childcare to test for radon and submit results to the Department of Children and Family Services ^[3]. Minnesota requires licensed family day care providers to test every five years and to retest after any structural change to the home ^[4].

Regardless of what your state mandates, the safest move is to test.

What is the EPA action level, and what happens if you exceed it?

The EPA's recommended action level is 4 picocuries per liter (pCi/L). At or above that number, the EPA says to fix the building ^[1]. Several states have written that same threshold into childcare regulation, so passing it becomes a legal duty to mitigate rather than a suggestion.

The EPA also flags risk between 2 and 4 pCi/L and tells homeowners to "consider fixing" in that range. Average indoor radon in U.S. homes runs about 1.3 pCi/L. Outdoor air averages about 0.4 pCi/L ^[1].

So what happens when a home daycare tests above 4 pCi/L?

In mandatory-testing states, the licensing agency usually requires you to submit the results. If they exceed the action level, you typically get a set window (often 60 to 90 days, depending on the state) to finish mitigation and retest. Operating while mitigation is pending is sometimes allowed, sometimes not. Iowa's childcare licensing rules require written documentation of mitigation and a follow-up test before full compliance comes back ^[5].

In non-mandatory states, a high reading does not trigger a licensing consequence by itself. But if a parent or inspector raises the issue, you are on much firmer ground having already tested and fixed the problem.

What types of radon tests are accepted for licensing purposes?

Two categories cover almost everything: short-term tests and long-term tests. For licensing, the test has to come from a certified lab, has to sit in the lowest level children use, and has to be placed correctly.

Short-term tests use a charcoal canister or an electret ion chamber. You set the device in the lowest livable level of the home for two to seven days, then mail it to a lab. Results come back within a week or two. Kits cost $15 to $30, plus $25 to $40 for lab analysis if it is not bundled in ^[6]. Most providers start here.

Long-term tests use an alpha track detector left in place for 90 days to a year. They read average annual exposure more accurately because radon rises and falls with weather, soil moisture, and how much you ventilate. They cost $25 to $50 all in ^[6].

States that require testing usually spell out the same three conditions: the test happens in the lowest level of the home used by children, the device comes from an EPA-listed or state-certified lab, and results come from that same certified lab. Do not grab a free kit that sat in a hardware store display for two years without checking whether the lab is on your state's approved list.

Some states, including New Jersey and Pennsylvania, require a state-certified radon measurement professional to run the test if the result goes toward initial licensure ^[10][9]. A professional test costs $100 to $300 depending on the provider and location.

First time doing this? Buy a short-term kit from a lab certified by the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB), place it right, and submit results the way your state asks. If you land above 4 pCi/L, hire a certified professional to confirm before you spend a dime on mitigation.

Where exactly in your home do you have to test?

Test in the lowest level of the home that children actually use. Radon comes up from the ground, so it collects heaviest in the basement and thins out on upper floors. Placement is where most rejected tests go wrong.

The rule is plain. If kids never go in the basement and you run everything on the first floor, test on the first floor. If children use the basement for naptime, play, or any regular activity, test in the basement.

EPA protocol for short-term tests: set the canister at least 20 inches above the floor, away from drafts, high heat, and direct sun. Keep it at least 4 inches from walls and at least 4 inches from the ceiling. Close windows and exterior doors for at least 12 hours before and during the test. Skip kitchens, bathrooms, and laundry rooms ^[1].

Inspectors reject a lot of results over placement. The inspector may ask where you put the device and for how long. Keep a note or a photo of the spot and the dates the kit was active.

If one level has separate areas (a finished basement split into a play area and a storage area, say), test in the area children occupy.

How often do you need to retest?

How often you retest depends on your state and your last result. Minnesota requires retesting every five years, and sooner if you make structural changes to the home ^[4]. Iowa requires retesting if you move the daycare to a different part of the home or after a major renovation.

Most other mandatory states require a retest within 24 months if your original result landed between 2 and 4 pCi/L, and require mitigation plus an immediate retest if you were above 4 pCi/L.

Even with no state schedule, the EPA recommends retesting every two years and after any major renovation that changes how air moves through your foundation ^[12]. Finishing a basement, adding a sump pump, replacing windows, or adding HVAC equipment can all shift radon levels a lot.

If you mitigate (the next section covers that), retest within 24 hours to 30 days after the system goes in. Your mitigation contractor usually handles that test as part of the job. After that, retest every two years to confirm the system still works.

What does radon mitigation cost, and who pays for it?

If your test comes back above 4 pCi/L, you mitigate, and you pay for it. The most common and effective method for homes is sub-slab depressurization (SSD). A contractor drills one or more holes through the concrete slab, runs a pipe up and out through the roof or an exterior wall, and adds a fan that pulls radon from under the slab and vents it outside before it builds up indoors.

SSD installation usually costs $800 to $2,500 for a single-family home, with most jobs landing in the $1,000 to $1,500 range ^[6]. Crawl spaces or multiple slabs push the price higher. The fan runs about $50 to $150 a year in electricity depending on the system and your rates.

Mitigation is a property improvement cost, and your licensing agency will not cover it. Some state radon programs offer low-interest loans or grants for certain groups, but childcare providers rarely qualify for residential assistance and rarely qualify for the commercial versions either.

Here is the good news. SSD systems work. Studies show they cut indoor radon by 50% to 99%, and the EPA says a properly installed system should bring most homes below 2 pCi/L ^[1].

Put mitigation in your business budget from day one. Your home daycare insurance policy almost certainly will not cover radon remediation as a loss, and your daycare liability insurance will not either. Treat it as a facility cost.

Does the CCDF require radon testing, and how does that affect subsidy-accepting providers?

No. CCDF does not currently require radon testing as a named standard. The Child Care and Development Fund regulations require states to set health and safety standards for licensed and license-exempt providers who accept CCDF subsidies, covering areas like emergency preparedness, safe sleep, and supervision ^[2]. Radon is not named in the federal CCDF regulations at 45 CFR Part 98.

States layer their own licensing rules on top of the CCDF floor. If your state's childcare licensing rules require radon testing, and you accept CCDF subsidy, you have to meet that state rule. Missing a state licensing requirement puts your subsidy contract at risk the same way it puts your license at risk.

Child Care Aware of America tracks how states carry out CCDF health and safety standards, and its state licensing work has found wide variation in environmental health requirements across states ^[7]. Some states count radon testing in their environmental health checklist. Others do not.

Not sure whether your state's CCDF plan touches radon? Call your Child Care Resource and Referral (CCR&R) agency. They can walk you through what applies to subsidy recipients specifically.

What happens at a licensing inspection if you have not tested?

In mandatory-testing states, showing up to an inspection without documented results is a compliance deficiency. It works like arriving without a working fire extinguisher. The inspector notes it, gives you a correction window (often 30 to 60 days), and may come back for a follow-up.

Repeat or uncorrected deficiencies can escalate to a probationary license, reduced capacity, or in serious cases suspension. The exact consequence depends on how your state classifies the violation. Some states rank radon testing as a Class A or critical deficiency because it hits child health directly.

In states where testing is recommended but not required, an inspector cannot cite you. But the ground is moving. If a parent later files a complaint about radon exposure, having no test on record looks bad.

Get the test done before your initial application, not after. It costs less than $30 and takes about a week. The documentation is ready when the inspector asks, and you are not scrambling.

Keep your results on file indefinitely, past the next renewal. If a claim or complaint ever lands, you want a paper trail that goes back years.

How do you find a certified radon test or a certified mitigator?

Two national bodies certify radon professionals: the National Radon Proficiency Program (NRPP), run by the American Association of Radon Scientists and Technologists (AARST), and the National Radon Safety Board (NRSB) ^[8]. Both keep searchable directories of certified testers and mitigators by state and zip code.

For do-it-yourself kits, the EPA points you to a state-approved lab or a lab that takes part in EPA-recognized quality programs. Your state radon program (most states run one, usually inside the department of health or environment) often keeps a list of approved labs and approved kits. The EPA's radon page is the fastest starting point ^[1].

For initial licensing in states that require professional testing, hire someone from the NRPP or NRSB directory. Ask for written proof of their certification number, then verify it online. That documentation goes into your licensing file.

The same NRPP and NRSB directories cover mitigation contractors. Get at least two quotes. The cheapest bid is not automatically the worst, but ask each contractor to show certification and explain what post-mitigation testing they include. A reputable contractor runs a post-installation test as standard practice.

Do you have to tell parents about radon test results?

Some states require disclosure. Most have no explicit rule. Either way, what you owe parents on this is worth thinking through, because the records may already be public.

In states that require test results on file, parents who request your licensing file may see them. In some states, licensing records are public. A parent searching your license record could turn up a past high reading even after you have mitigated.

So get ahead of it. Post your most recent test result (or a short summary) in the same place you post your license and your health and safety policies. If you mitigated, say so, and include the post-mitigation number. A documented fix reads far better than a buried result that surfaces later.

Building your parent handbook or health and safety documentation? The ChildCareComp compliance toolkit includes a radon disclosure template that matches the common state formats. Filing environmental health records next to your general daycare cleaning and sanitation logs shows parents how seriously you take the physical space.

What if your home daycare is in a basement or below-grade space?

Running a licensed home daycare in a basement is legal in many states, but it almost always comes with extra conditions, and radon is the big one.

Below-grade spaces carry the highest average radon levels because they sit closest to the soil source and swap out less air per hour. If children sleep, eat, or spend most of their day in a basement, the exposure math is worse than for a first-floor or above-grade room.

Some states flatly ban below-grade primary care spaces. Others allow them with enough windows, egress, and ventilation. If your state allows below-grade daycare space, radon testing is almost certainly required for that area even when it would not be required for above-grade providers.

Test a basement space and come back above 4 pCi/L, and you have three moves: mitigate and retest, shift the daycare to an above-grade level and retest there, or close the basement to children for good. You cannot average the basement reading with a first-floor reading and call it compliant.

Before you renovate or finish a basement for childcare, test first. A pre-renovation test costs the same $15 to $30 as any other test, and it tells you whether you have a problem before you sink money into flooring, insulation, and drywall.

Frequently asked questions

Is radon testing required for all licensed home daycares in the U.S.?

No, there is no federal mandate. Roughly 20 to 25 states require or strongly recommend radon testing for licensed home daycares as of 2024. States including Illinois, Iowa, Minnesota, New Jersey, Pennsylvania, and Virginia have written testing requirements in their childcare licensing rules. If your state is not on that list, check with your state licensing agency directly, since informal requirements are common.

What is the EPA radon action level for childcare facilities?

The EPA's action level is 4 picocuries per liter (pCi/L) for all indoor spaces, including childcare settings. At or above that level, the EPA recommends fixing the building. Most state childcare licensing rules that address radon use the same 4 pCi/L threshold. The EPA also says levels between 2 and 4 pCi/L carry real risk and you should consider mitigation at those readings too.

How much does a radon test cost for a home daycare?

A DIY short-term charcoal canister test costs $15 to $30 for the kit plus lab analysis, or up to $40 if lab fees are separate. A long-term alpha track test runs $25 to $50. If your state requires a certified professional to conduct the test for initial licensure, expect $100 to $300 depending on your location and the contractor.

How long does a radon test take?

Short-term tests sit in your home for two to seven days, then go to a lab. Results come back within one to two weeks of mailing. Long-term tests stay in place for 90 days to one year for a more accurate average. For licensing deadlines, a short-term test is faster, but some states require a long-term test for initial licensure to get a true annual average.

Can I use a hardware store radon test kit for my licensing inspection?

Only if the kit comes from a lab certified by NRPP, NRSB, or your state radon program. Many hardware store kits are from certified labs and are fully acceptable. Check the package for the lab certification number, then verify it on the NRPP or NRSB website before you buy. A kit from an uncertified lab will not satisfy most state licensing requirements even if the result looks fine.

Does CCDF (federal subsidy) require radon testing for home daycares?

No, the federal CCDF regulations at 45 CFR Part 98 do not name radon testing as a required health and safety standard. However, states set their own childcare licensing rules, and if your state requires radon testing as a licensing condition, that requirement applies to subsidy-accepting providers too. Non-compliance can jeopardize both your license and your subsidy contract.

How often do I need to retest for radon once I am licensed?

Minnesota requires retesting every five years. Iowa requires retesting after structural changes. Most mandatory-testing states require retesting within 24 months if your first result was between 2 and 4 pCi/L, and immediate retesting after mitigation if you were above 4 pCi/L. Even without a state deadline, the EPA recommends retesting every two years and after any significant renovation.

What happens if my home daycare tests above 4 pCi/L?

In mandatory-testing states, you are required to mitigate and retest. Most states give you 60 to 90 days to complete mitigation. You may be allowed to continue operating during that window, or you may face a temporary capacity reduction, depending on your state's rules. Sub-slab depressurization, the most common mitigation method, costs $800 to $2,500 and typically brings levels below 2 pCi/L.

Does radon mitigation cost count as a business expense?

Yes. If the space is used for your licensed daycare business, radon mitigation is a deductible business expense on your Schedule C or Schedule F. The cost of the test itself is also deductible. Keep receipts and the contractor's invoice. Consult a tax professional familiar with home-based childcare businesses, since the home office and business-use percentage rules apply to mixed-use spaces.

Do I have to disclose radon test results to daycare parents?

Most states do not have an explicit disclosure rule, but licensing records in many states are public, meaning parents could find your test results anyway. Best practice is to post your most recent result proactively alongside your license and health and safety policies. If you mitigated, include the post-mitigation result. Transparency here protects you legally and builds parent trust.

Can I operate a home daycare in a basement if radon levels are high?

Not without mitigation. If children use a below-grade space and the radon reading exceeds 4 pCi/L, you must either mitigate and retest, move childcare operations to an above-grade level, or permanently close the area to children. Some states prohibit below-grade primary childcare spaces regardless of radon levels. Check your state's physical space requirements before investing in a basement setup.

Where do I find a certified radon tester or mitigator?

Use the searchable directories at the National Radon Proficiency Program (NRPP, aarst-nrpp.com) or the National Radon Safety Board (NRSB, nrsb.org). Both list certified testers and mitigators by zip code. Your state radon program, usually housed in the department of health, also keeps a list of state-approved professionals and labs. Always verify a contractor's certification number before hiring.

What if I recently renovated my home daycare space? Do I need to retest for radon?

Yes, you should retest after any significant structural work. Finishing a basement, adding a sump pump, replacing windows or exterior doors, or modifying HVAC systems can all change how air flows through your foundation and affect radon levels substantially. Minnesota's licensing rules explicitly require retesting after structural changes. Even if your state does not, it is a sound practice to document a fresh test after renovation.

Sources

1. U.S. EPA, A Citizen's Guide to Radon: EPA action level is 4 pCi/L; radon causes about 21,000 lung cancer deaths per year; average indoor level is 1.3 pCi/L; SSD reduces levels by 50–99%
2. U.S. Administration for Children and Families, Child Care and Development Fund (CCDF): CCDF regulations require states to establish health and safety standards but do not name radon testing as a required standard
3. Illinois Department of Children and Family Services, Child Care Licensing: Illinois requires family homes licensed for childcare to test for radon and submit results to DCFS
4. Minnesota Department of Human Services, Family Day Care Licensing Requirements: Minnesota requires licensed family day care providers to test for radon every five years and after structural changes
5. Iowa Department of Health and Human Services, Child Care Licensing: Iowa requires written documentation of radon mitigation and a follow-up test before full compliance is restored
6. U.S. EPA, Consumer's Guide to Radon Reduction: Short-term test kits cost $15–30; long-term kits $25–50; sub-slab depressurization typically costs $800–2,500
7. Child Care Aware of America: Child Care Aware tracks state implementation of CCDF health and safety standards and finds significant variation in environmental health requirements
8. American Association of Radon Scientists and Technologists (AARST), National Radon Proficiency Program: NRPP maintains a searchable directory of certified radon testers and mitigators by state
9. New Jersey Department of Children and Families, Child Care Licensing: New Jersey requires radon testing for all licensed child care centers and home daycares at 4 pCi/L threshold
10. Pennsylvania Department of Human Services, Child Care Certification Requirements: Pennsylvania requires radon testing by a state-certified professional for licensed child care homes
11. Virginia Department of Social Services, Family Day Home Licensing Standards: Virginia requires radon testing at application for licensed family day homes
12. U.S. EPA, Indoor Air Quality (IAQ): EPA states outdoor air averages 0.4 pCi/L radon and recommends retesting every two years and after major renovations