Radon Testing At Home: A Landlord's Guide

As a landlord, you are responsible for understanding the dangers, laws, and proper testing procedures for radon. This guide will teach you what you need to know about this colorless, odorless gas and how you can ensure that it isn’t present in your rental properties.

Radon in Rental Properties

Landlords and property owners are required to make a wide variety of disclosures, both to governing authorities and to their renters, regarding the normative nature of their residence. These disclosures are designed to ensure that renters are always properly informed about the inherent risks of choosing one property over another.

Just as landlords are required to disclose the presence of lead paint to a prospective renter, landlords are often required to provide testing and documentation regarding the presence of radon, an invisible yet hazardous radioactive gas that is known to permeate many American homes and apartment buildings. Knowing what radon is and how to manage it is key to maintaining your rental’s indoor air quality.

Whether you are a new landlord or a veteran of the industry, you are bound by state and federal laws pertaining to maintaining safe radon levels in your properties. There’s never a better time to review these regulations and apply their requirements to your standard operating procedures.

In addition, there are some active steps you can take to track and mitigate the effects of radon in your properties. This guide will also cover steps you can take to test for radon, as well as steps you can follow to fix an identified leak.

If you own a property, then radon is your responsibility. Read this guide to help yourself develop an effective radon mitigation system.

What is Radon?

Before we can address your responsibility to address radon in your rental property, we need to first establish what radon is and why it is a persistent threat to homes and apartment buildings across the United States.

According to the Environmental Protection Agency (EPA), radon is “a colorless, odorless and tasteless gas produced by the decay of uranium.” Radon gas that is trapped in the ground is often released during commercial and residential construction projects. Because of its atomic nature, radon is able to seep into homes through most common construction materials, including concrete blocks, mortar, sheathing paper, wood paneling, and insulation.

Having derived from uranium, radon is radioactive. Radon particles emit alpha radiation, the same type of radiation produced by strongly radioactive elements like plutonium.

Harmful Effects of Radon Exposure and Inhalation

Like uranium proper, radon is a considerable threat to human health. The Surgeon General has rated radon as the second leading cause of lung cancer in the United States (behind smoking). For non-smokers, radon inhalation remains the leading cause of lung cancer in this country. Annually, radon has been estimated to contribute to between 7,000 and 30,000 deaths.

If left unchecked, entire families can be continuously exposed to this harmful gas without ever sensing it. Radon.com notes that a family who lives in a radon-infected home receives nearly 35 times as much radiation as they would receive if they stood next to a radioactive waste disposal site.

Radon Regulation

As expected, both state and federal governments have gone to great lengths to regulate radon exposure in order to protect the populous. While implementing radon detection is heavily recommended for homeowners, rental property owners and landlords in many jurisdictions are required to implement radon testing plans for all of their properties. If proper regulations are not followed, landlords and property owners open themselves up to severe liability.

Simply put, both short-term and long-term radon exposure are no laughing matters. As a landlord, it is your responsibility to know about relevant laws and implement necessary preventative measures in order to protect your renters from the noxious effects of radon.

Landlord’s Liability for Radon

Landlords, property owners, and other land managers are often required by both state and federal laws to persistently test for and inform patrons of radon in their living quarters. Because of the severe nature of non-compliance, enforcement authorities tend to impose considerable fines when proper regulations are not followed.

In general, most laws concerning radon and landlords involves proper disclosure of its presence on the property. After building or purchasing a property, landlords must run certified radon tests in all of their units in order to properly assess the likelihood of radon exposure per location. For more information on how to run these tests, continue reading in “How to Test for Radon in your Rental Properties”.

Once these radon levels have been properly assessed, most states require some form of documented disclosure to be made to tenants. This disclosure can be made in a variety of methods (depending on the jurisdiction), including on the lease, the rental agreement, or as a separate documented form.

In some cases, both the landlord and renter will need to sign radon-related paperwork to certify a mutual understanding of radon exposure risks on the property. No matter the requirements, it is in the landlord’s best interest to always do their due diligence and check with their attorney to ensure their disclosures are up to snuff.

Specific laws and regulations governing radon disclosure vary from state to state and jurisdiction to jurisdiction. In order to learn more about landlord-specific rules in your area, continue reading below.

Laws and Regulations Governing Radon

As is often the case, specific laws and regulations vary from state to state. In fact, some federal regulations regarding radon apply to all states, regardless of local laws. As such, it is worthwhile to learn about your specific state’s radon management rules and implement them as soon as possible.

For the purposes of this guide, these regulation categories will be split into several sub-groups. Every state will appear in one or more groups, so be sure to find your state and read further into your legally mandated radon disclosure requirements.

For more information on state-by-state radon disclosure and testing requirements (as well as links to relevant state-specific laws), visit the Policy Surveillance Program.

Requirements to Disclose Radon Levels to Tenants

In the United States, only four states currently require landlords to disclose present radon levels in their properties as a part of their lease agreement. These states are Maine, Illinois, Colorado, and Florida.

In these states, landlords must include information regarding radon, its risks, and its present level at the desired property.

At this time, all other states do not explicitly require radon disclosures be made to renters. However, localized jurisdictions (such as cities) may require disclosures be made on behalf of the city. In this case, you may still need to make some form of disclosure to remain in compliance with city laws.

Requirements to Disclose Radon Levels in Real Estate Sales

Some landlords also take part in real estate sales. As such, it is important to know that most states require radon disclosure information to be provided before a home is sold. This is the case in all US states except for Idaho, Wyoming, Utah, Arizona, New Mexico, North Dakota, Missouri, Arkansas, Georgia, Alabama, Virginia, West Virginia, Vermont, and Massachusetts.

As with rental agreements, states requiring disclosures in real estate sales often require such disclosures to be made in writing, if not part of the property purchasing agreement proper.

Radon Disclosure Agencies

Each state includes one or more groups through whom radon disclosures may be made. These can vary from state agencies (such as a state emergency management agency or housing department) to independent industry groups (such as a realtor’s association). In either case, these bodies often hold the authority to enforce radon disclosure policies as well as keep records on statewide radon levels.

Currently, 23 states primarily monitor radon disclosure rules through a state agency or department. These states include Washington, Oregon, Montana, Texas, Kansas, Minnesota, Wisconsin, Illinois, Iowa, Michigan, Tennessee, Ohio, Florida, North Carolina, South Carolina, Pennsylvania, Delaware, Maryland, New York, Connecticut, Rhode Island, New Hampshire, and Maine.

On the other hand, the following states use a state real estate board and/or a statewide association of realtors to regulate radon disclosure policies: Washington, California, Nevada, Colorado, Nebraska, South Dakota, Arizona, New Mexico, Utah, Texas, Kansas, Minnesota, Missouri, Illinois, Kentucky, Indiana, Tennessee, Louisiana, Mississippi, Georgia, Florida, North Carolina, South Carolina, Pennsylvania, New Jersey, Maryland, Delaware, Connecticut, Rhode Island, Massachusetts, Vermont, New Hampshire, Maine, and the District of Columbia.

Of note, some of these states use an outside industry-focused association in addition to a statewide government agency.

Radon Testing in Sensitive Areas

In general, many states require some form of radon testing either before or during regular occupancy – whether the property is rented or owned. However, several states require heightened testing in “sensitive” areas where exposure to vulnerable groups is more likely. If you rent space to these types of groups or industries, you may be required to perform more regular radon tests.

For example, several states mandate regular radon testing on properties used as daycare centers (both public and private). While this traditionally involves standalone buildings, in-home daycares are sometimes subject to these regulations as well. These states include Idaho, Iowa, Illinois, Michigan, Florida, Connecticut, Rhode Island, New Jersey, and New Hampshire.

Penalties for Misrepresenting or Falsifying Radon Tests

Most states that include radon testing laws also include penalties for misrepresenting or falsifying required disclosures of said tests. This can include disclosures made to governing authorities and to customers, such as renters. Specific penalties vary from state to state, including classification of such an act as a civil or criminal penalty.

The following states classify radon testing falsification as a civil offense: California, Nebraska, Kansas, Illinois, Indiana, Kentucky, Tennessee, Ohio, Pennsylvania, South Carolina, and the District of Columbia.

The following states classify radon testing falsification as a criminal offense: Nebraska, Kansas, Iowa, Illinois, Indiana, Michigan, Ohio, West Virginia, Florida, New Jersey, and New Hampshire.

There are some overlaps between these two categories. This is primarily because some states allow for criminal charges in cases of long-term or intentional negligence on the part of the property owner.

Also, certain jurisdictions allow tenants to file claims against landlords based upon certification that the premises are “uninhabitable” due to negligence on the landlord’s part. Though these statutes may not include radon exposure by name, they may still be applied broadly if the tenant is able to produce tested proof of higher-than-standard radon levels.

How to Test for Radon in your Rental Properties

Testing for radon in and around your properties can be one of the most proactive steps towards keeping your tenants safe from passive radon exposure. In fact, some states (as described above) mandate regular testing for certain types of living spaces, including homes, apartments, and daycares.

As such, it is important to know how to perform a radon test, as well as what to do with your test results afterward.

Radon Testing Terminology

Before jumping into the testing procedure, however, it is important to understand the terminology and mitigation goals that these tests strive to meet.

First and foremost, radon gas levels are measured in picocuries per liter of air in a 24-hour period. Often, this radon measurement is abbreviated to “pCi/L”. This metric is used to demonstrate how much disintegration from a radioactive gas (in this case, radon) is taking place in the location that the test is being performed.

The EPA currently measures all radon levels against their “action level,” or in other words, the level at which the amount of radon gas detected in an area poses an acute risk to inhabitants. Currently, the EPA’s action level is set at 4 pCi/L. Even if a given test comes in lower than this figure, there is often more a landlord can do to minimize radon exposure on their properties further.

This being said, no amount of radon exposure is safe, according to the EPA. Instead, minimizing the presence of radon in homes, apartments, and other sensitive areas like schools is the best way to mitigate the potential risks brought on by the radon’s radioactivity. Though not a perfect parallel, some compare this to minimizing one’s exposure to UV rays from the sun as a means of lowering one’s chance of acquiring skin cancer.

To this end, the EPA estimates that of every person exposed to 4 pCi/L of radon on a regular basis (at home, at school, or in the workplace), nearly 1 in 100 of them will eventually die of radon-related illnesses. This is compared to other EPA regulated carcinogens – including asbestos, arsenic, cadmium, radium, formaldehyde, and more – which carry a 1 in 100,000 likelihood of death related to overexposure.

In this way, radon carries a nearly 1000 times greater likelihood of death compared to standard levels of exposure to other dangerous particles.

Radon Testing Procedure

As it were, testing is the only way to discover how much radon is present in a given living space. Because of its colorless, odorless, and tasteless nature, radon cannot be detected but through a highly-sensitive, specialized test to check for it the gas or its various components. Acute symptoms to radon exposure are nearly nonexistent, meaning most effects do not show up for years after extended exposure.

Passive Radon Tests

Most radon tests are a small, hand-sized envelope containing special testing designed to react to the presence of radon. This makes radon test easy to store and use with convenience at your own properties.

Most radon tests are sent away to be properly analyzed by trained experts. With this in mind, the first step to performing a radon test is to fill out any documentation that came with the test as instructed. This will likely include your name and location (city and state) that the test was performed in. Also, you will generally be asked about timing details, including when the test started and ended. In some cases, this information is written directly on the testing envelope.

After filling out the relevant paperwork, the test proper can begin. To do this, carefully open the marked end of the envelope as indicated in the instructions. Inside, you will likely see a small, teabag-like satchel, a popsicle-like stick, and an oval-shaped piece of cardboard. The first item is the testing mechanism itself, while the other two components are designed to keep the packet open during the next steps.

With the packet open, firmly hold the entire packet with both hands and press in on both sides. Continue doing this until the oval-shaped cardboard piece is maneuvered into place and holding the entire packet open on its own. At this point, the packet is ready to begin testing.

With the packet ready, you may now hang the radon test in the appropriate space. If you are a landlord, this will mean placing at least one test in each of your properties, on the lowest floor of the building. Hang the test in an open area and leave it be for as long as the instructions require (often several hours or up to several days).

Once the testing period is complete, recollect the radon test. Using the protruding popsicle stick-like apparatus, pull up on the cardboard oval until it is freed from the envelope. Discard both of these pieces.

Then, remove the pre-seal tab inside the rim of the envelope and securely close the envelope, as specified in the instructions. At this point, the test is ready to be returned to whoever will analyze it and provide you with timely results.

As described below in “Recommended Radon Detection Products”, radon test kits like these can be acquired from a variety of sources, including both physical and digital retailers.

Continuous Radon Monitoring

Another method of testing for radon in a given space is through the installation of a long-term radon monitoring system. This may also be a worthwhile solution after running a standard radon test, finding positive results, and instituting remedial actions. This type of continuous monitoring can help evaluate changes in radon dispersion in a space over time.

Most modern continuous radon monitors are digital, which use special diodes to detect and measure the amount of radon in the air without the need for a chemical compound. Most models are capable of running both short and long tests (between 1 and 7 days), as well as providing continuous testing to evaluate time-sensitive changes.

Continuous radon monitors have the added advantage of not needing to be sent away for an evaluation. Instead, most digital models read out in an easy-to-interpret language that will allow you to simply and easily determine if one of your properties has too much radon present.

When you purchase a continuous radon monitor (more details below in “Recommended Radon Detection Products”), be sure to evaluate if it is battery-powered or if it requires a wall plugin. With this in mind, you can take the first installation step. With the power source in mind, find a space on the lowest floor of each of your properties and install the monitor several feet above the floor.

In general, it is best practice to place your continuous radon monitors away from direct sunlight and out of spaces known for trapping moisture. Also, try to avoid place the monitor in an area with vents or a draft, as this can interfere with the monitor’s ability to accurately read the amount of static radon in the air.

As noted, you will only need one monitor per building. As a result, continuous monitors can be seen as a more cost-effective, long-term solution when compared to one-off passive radon tests.

In any case, you should make a concerted effort to regularly check and record the results from these monitors (even if the result is “0”). After implementing continuous monitors on your properties, you should check the results at least once a week for their first month of use (in order to establish baseline data). Beyond the first month, you can set a schedule that will allow you to properly inform each new tenant of their space’s radon levels.

What to Do with Radon Test Results

First and foremost, you should write down the results from each and every radon test performed in a consistent location that can be referenced later, if necessary. Doing so may save you time and hassle later if a tenant or regulator inquiries about levels of radon at one of your properties in the recent past.

With the actual results, though, you should check their outputs against the EPA’s “action level” for radon – 4 pCi/L. If the results are at or near this figure, you may have a significant radon problem at your property that you must act to remedy immediately (see “How to Fix a Radon Leak” for more info).

However, in most cases, your radon test results will come in significantly lower than the EPA’s “action level.” This does not mean that you are home free. Remember that no amount of radon exposure is safe, so any sustained presence in your properties could be putting your tenants at risk.

If you notice any type of pattern in your radon test results (even if they are “low” when compared to the EPA’s” action level”), it is in your best interest to mitigate your liability by implementing a plan to fix your properties’ radon leaks.

How to Fix a Radon Leak

Average radon levels in the United States, as defined by the EPA, are between 0.4 and 1.3 pCi/L. If you find that one or more of your properties have radon levels above this average, then you have proper cause to fix the abundance of radon leaking into these buildings.

There are several different methods for helping to mitigate or resolve a radon leak in one of your properties. Remember that no one of these solutions is likely to entirely solve a radon leak. You will likely need to implement several of these fixes before a noticeable change in radon levels becomes apparent.

Sealing Foundation Cracks

Sealing cracks in your properties’ foundation should be the first step to mitigating ambient radon gas that is leaking up from the soil or bedrock. This is considered a basic approach and is recommended to all property owners as broadly important maintenance.

However, the EPA states that sealing foundational cracks alone will not fully fix a radon problem. They note that this is a common misconception that property owners and homeowners should not fall for.

Sub-Slab Depressurization System

In most cases, a sub-slab depressurization system will be necessary to collect and off-gas hazardous radon fumes away from a problematic property. This can be accomplished through a specialized system of vent pipes and fans installed directly into your property and run nearly continuously.

In many cases, these systems resemble those implemented to aerate crawl spaces. To this extent, they work like a fireplace chimney as they collect up radon gases trapped beneath the foundation of your home and draw it upwards through a vent pipe for release away from the home.

These types of depressurization can represent a significant renovation, especially if it is being implemented on an owned property in which tenants presently live. That being said, the cost of installation far outweighs the dangers of not acting to resolve such a hazardous problem.

Hire a Radon-Reduction Contractor

Whether you plan on installing a sub-slab depressurization system or simply need to consult with an expert about the best radon maintenance plan for your properties, a radon-reduction contractor is the best expert to turn to. Depending on where you live, several radon-reduction contractors may be available and able to offer their services for your various properties.

Radon-reduction contractors in major enforcement states are required to meet the state’s specific radon reduction standards. Otherwise, the EPA recommends meeting their own standards outlined in ASTM E 2121. In any case, you should be vigilant to ensure that your hired contractor completes their work as described in accordance with appropriate regulations (as you would with any contract work on your properties).

The Importance of Fixing a Radon Leak

Remember that it is better to fix a radon problem before putting a property on the market rather than having to work to resolve a radon leak while the space is occupied. In fact, it is far better to be proactive than to be caught ignoring the problem by a tenant or regulating authority. Failing to fix a known leak can open you up to serious liability and loss of future business.

Recommended Radon Detection Products

Because of its widespread threat throughout the United States, a wide number of radon detection and mitigation products are available on the consumer market today. Though you are, in your landlord capacity, a professional when it comes to property management, you’ll still be taking advantage of consumer-grade options when it comes to radon checking your properties.

Below are among the most common products that homeowners and landlords alike reach for when working to mitigate radon. Each product is used in a different scenario and should not be compared to one another one-for-one. If you have questions about which product is right for you, consult with a radon-reduction expert in your area.

First Alert RD1 Radon Gas Test Kit

First Alert RD1 Radon Gas Test Kit

First Alert RD1 Radon Gas Test Kit

This is a standard test kit for at-home passive radon testing.

*At the time of publishing, the price was $13.98. Image from Amazon listing.

Available at most home maintenance stores such as Lowes and Home Depot, this kit has become an easy-to-access standard for passive radon testing. These tests are even available from online retailers such as Amazon, where they would be bought in bulk. These bulk test purchase may be ideal if you need many individual tests for your many properties.

In particular, these tests are designed to be quick and effective, with results returning in ~72 hours after each envelope is mailed back to the analysis lab in Texas. In addition, instructions for use are clearly printed on the package, making the test easy to use for first-timers.

Radon.com Radon Gas Test Kit

Radon.com Radon Gas Test Kit

Radon.com Radon Gas Test Kit

This an affordable, easy-to-use test kit vetted by Radon.com.

*At the time of publishing, the price was $15. Image from Radon.com listing.

Another fantastic choice when it comes to running one-time radon tests on your properties is Radon.com’s radon gas test kit. It is both easy to use and easy to purchase. Radon.com creates these proprietary tests and makes them easy and affordable to acquire directly from their source (including in bulk).

This style of passive radon test has become more and more popular lately, with Radon.com claiming that their product has been used in millions of living spaces around the country. Part of this popularity may also derive from its ease of results access, which are quickly available online.

Also, because this kit has become excessively common, its precise use and implementation has been described above in this guide’s “How to Test for Radon in your Rental Properties” section.

Airthings 223 Corentium Portable Home Radon Detector

Airthings 223 Corentium Portable Home Radon Detector

Airthings 223 Corentium Portable Home Radon Detector

This is a popular choice for homeowners looking for long-term or continous radon gas tests.

*At the time of publishing, the price was $179.00. Image from Amazon listing.

A popular solution for performing long-term or continuous radon gas tests, this detector is capable of calculating both long-term and short-term radon quantities without the need for a send-away lab analysis. In fact, this model’s easy to read interface has made it a favorite among homeowners and landlords alike.

Of special note for landlords, this detector is capable of printing out reports for each of its tests. This allows you to keep records of when tests were performed on your properties in case a tenant or regulator ever has questions about your radon mitigation plans.

Airthings Corentium Pro Digital Radon Monitor

Airthings Corentium Pro Digital Radon Monitor

Airthings Corentium Pro Digital Radon Monitor

This is a trusty long-term solution for radon testing. It’s also portable.

*At the time of publishing, the price was $1,299.99. Image from Amazon listing.

If you’ve identified an ongoing radon problem on one of your properties and are looking for a better long-term monitoring solution, this model can accomplish this task and more. Built with professionals in mind, this compact detector and monitor interfaces with an easy-to-navigate app where you easily find an archive of your previous test results.

This model is also fully AARST/NRPP-certified as well as fully tamper-proof, ensuring continuous compliance with relevant mandatory regulations regarding radon testing. Perhaps most importantly for landlords, this monitor allows you to access all of its data from a computer in order to analyze, compare, and print out up to five years’ worth of data.

EPA Guide

The EPA also provides an online Home Buyer’s Guide to radon testing products and procedures. Many landlords will find the information included in this booklet – including how to procure and operate a radon test – very helpful.

Frequently Asked Questions (FAQ)

Where does radon come from?

Created by the decay of naturally occurring uranium deep in the ground, radon percolates to the surface over time after escaping from natural chambers within bedrock or limestone.

Radon can be found predominantly in soil as a result, as well as anything built upon that soil. In the outdoors, radon gas usually dissipates and is not a threat to human health. However, homes and buildings have a tendency to trap radon gas as it rises, creating a more acute, undetectable harm.

Is radon common in my area?

Radon is well-known to be present nearly everywhere in the world, in some capacity. The United States is included in this broad distribution, though the EPA has identified some areas as having a greater preponderance of radon gas than other areas.

To illustrate this nationwide distribution, the EPA has created an updated illustrated map that breaks down expected radon risk by county for all states and territories. This map can serve as a major asset when evaluating preliminary radon risks in your area.

What is a “safe” or “acceptable” radon level?

The EPA is firmly clear on this matter: no amount of radon exposure is “safe.” Like other environmental carcinogens like UV rays and second-hand smoke, any exposure can be linked to increased likelihoods of illnesses over the course of a person’s life.

Because full elimination of radon exposure is very difficult, the EPA implores homeowners and property managers to strive for minimizing radon’s presence in their dwellings. To quantify this, the EPA recommends taking action if you find (using a radon test or monitor) that your radon burden is close to or above 4 pCi/L. Even amounts of radon below this level exponentially increase the likelihood of cancer after long-term exposure.

Can I test for radon on my own? How do I operate a radon test?

Not only can you test for radon on your own, but as a property manager, you are often legally obliged to do so on behalf of your tenants. For more information on how to operate various types of radon tests, see this guide’s “How to Test for Radon in your Rental Properties” section.

Also, for more information on your legal obligations relating to radon testing and maintenance see this guide’s “Landlord’s Liability for Radon” section.

Where can I purchase radon tests and radon monitoring equipment?

Radon testing and monitor equipment can be found at a variety of retailers, including brick-and-mortar stores like Lowes or Home Depot as well as online retailers such as Amazon.

Additionally, special interest outlets like Radon.com provide excellent information on the best radon equipment available, as well as providing affordable testing options of their own.

For more info on where to procure radon testing equipment, see this guide’s “Recommended Radon Detection Products” section.

What should I do if I find unacceptably high radon level in one of my properties?

First and foremost, don’t panic. Radon leaks can be resolved through careful planning and continued monitoring. High levels of radon can be managed and resolved. Apart from contacting a local radon-reduction specialist, there are also several go-to numbers you can contact in order to plan your next steps.

1-800-55RADON (557-2366) – Operated by Kansas State University in partnership with the EPA, this line can provide live help for radon-related questions.

1-800-644-6999 – This line can provide general information about fixing radon leaks in a variety of dwelling types.

1-800-SOS-RADON (767-7236) – Operated by Kansas State University in partnership with the EPA, this line allows you to purchase radon testing equipment over the phone.

Sources for More Radon Information

Many government and special interest groups have taken the time to create a wealth of resources to inform the public about the dangers of radon, as well as what steps they can take to minimize their exposure.

Though many of these resources are geared at homeowners, much of the information still applies to tenants and their landlords.

Consult these resources for further information on the dangers of radon, as well as how you can plan to address its presence in your properties.

Here are some pages to refer to from the Environmental Protection Agency (EPA):