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We've never shied away from answering a question, and we don't believe in such a thing as a dumb question. If you're unsure where to start or find yourself confused or overwhelmed, we compiled a handy FAQ to help get you sorted out.

For any questions we haven't answered here, email us at or call us at 1 888 472 3664 or 905 985 5545, and we'd be happy to answer them.

  • What is Radon?
    Radon is a naturally occurring radioactive soil gas that when inhaled can cause lung cancer. For more information, please visit our About Radon page.
  • Where does Radon come from?
    Radon is created from the breakdown of trace amounts of Uranium breaking down through its decay chain. This Uranium has been spread across North America by the glaciers from the last few ice ages scraping the bedrock up and depositing it everywhere. For more information, please visit our About Radon page.
  • Why should I test for Radon?
    Every house has some level of radon. The question is how much is present. The only way to detect Radon is with specialised testing devices. It's odourless, colourless, and present at such low concentrations that if it wasn't radioactive, we couldn't detect it.
  • Who is at risk?
    Everyone is at risk. Radon is a naturally occurring soil gas, meaning it's present in nature, but it can build up to dangerous levels inside of buildings. It doesn't matter if the buildings are built on the ground or if they are raised above ground such as on posts like some areas in Florida have, they can still test positive for Radon.
  • What are the statistics for getting Radon-induced lung cancer?
    Take Action on Radon pamphlet says 200 Bq = 2% non smoker, 17% smoker.
  • How does Radon cause lung cancer?
    The dangerous alpha particle that is created when Radon radioactively decays is very different from the gamma particle radiation that most people are familiar with. While concrete or lead is required to shield the body from gamma particles, alpha particles require little more than a sheet of thick paper to be effectively blocked. This is why Radon does not cause skin cancer, as our protective layer of dead skin cells are effective at blocking it. However, when we inhale Radon, the inside of our lungs have no such protection, and the cells there can receive the full, devastating effect of these alpha particles.
  • Does exposure to Radon cause other health effects besides lung cancer?
    There are currently no other health effects confirmed to be caused by Radon, but several other cancers have been linked, but not confirmed. These include brain cancer, childhood leukemia, throat, and stomach cancers.
  • How does Radon get into your home?
    In simple terms, there is less pressure inside the house than there is in the soil. Thus the soil gas that contains Radon will find any openings it can, and seep in through tiny cracks or openings.
  • What is the average level of Radon found in homes in Ontario?
    The average Radon level in Ontario is 83.3 Bq/m³.
  • What is the percentage of homes that have Radon higher then 200 Bq/m³?
    The Canada wide average is approximately 1 in 7 homes (~14%), but some of the more recent testing has shown that Ontario is much closer to 1 in 5 (~22%) homes being above 200.
  • Are any homes Radon-free?
    No. It is virtually impossible to completely eliminate Radon, which is why one of the Radon industry’s principles is "ALARA" or "As Low As Reasonably Achievable."
  • Which homes have a problem? What factors can contribute to this?
    Newer, tighter, or remodelled homes are more likely to have elevated levels of Radon as they capture both heat and Radon better. If you have large openings through the slab, such as open sump pits, floor drains that go to the dirt, or well water lines that have been fed through a large pipe, those can contribute Radon into the house.
  • At what point should I be concerned about Radon?
    We strongly consider anything over 200 Bq/m³ be mitigated, and anything between 100 Bq/m³ be considered for mitigation as the Health Canada action level is 200 Bq/m³, and the World Health Organization's action level is 100 Bq/m³. However, it is ultimately a decision you will make as you will need to determine what level of radiation from Radon you're comfortable with in your home.
  • Should I tell my doctor about my Radon levels?
    If you are worried about the results of exposure to Radon, then informing your family doctor is your best bet to ensure that you stay healthy. Many factors go into determining if you are at risk for lung cancer, and your doctor is the best person to understand and plan any actions moving forward.
  • What is Radon testing?
    Radon testing allows you to determine what amount of Radon gas you are being exposed to, as there are only a few ways to actually detect it.
  • How long does a test take?
    If you're using one of the test kits supplied by Mr. Radon®, then your testing process will be either 5 days or up to 1 year in duration. If you've gone another route with testing, please refer to the manufacturer's guide for further details.
  • What tests do you offer or recommend? Why?
    Mr. Radon® offers both a short-term test kit, which is great for finding out your Radon levels quickly in a cost-effective manner; as well as a long-term test kit which provides a more accurate reading over an extended period of time. There are also several excellent electronic Radon Monitors that we recommend that are available via Amazon, or Best Buy, such as the AirThings Corentium, or the AirThings Wave, that will give you a constant update to your Radon numbers.
  • What tests don't you recommend? Why?
    We don't recommend Charcoal canister test kits, as their short duration times and sensitivity to all sorts of environmental factors makes them very susceptible to failure, and false-low test results.
  • What are the differences between the short-term and long-term test kits?
    The primary difference between the two test kits resides primarily in the way that they record the presence of Radon. The short-term test kit uses a charged plate that loses a little bit of voltage each time it is struck by Radon's radioactive decay, and the long-term test kit has a piece of plastic inside that has never been exposed to outside air, that becomes marked by the radioactive particles it's testing for. These marks are counted later in the lab with a microscope after acid-etching in order to determine exposure. The secondary difference is that the short-term test kits are reusable on our end, as the kit can be reused several times until the voltage is completely depleted, whereas the long-term test kits are single-use. Finally, the short-term test kits are a total of 5 days in length and the long-term test kits are 90 to 365 days in length.
  • How big is the test kit?
    While there are a few different sizes of test kits available, our short-term test kits are approximately 4” (100mm) across, and 3” (75mm) tall, and our long-term test kits are approximately 1.25” (32mm) across, and 0.5” (12.5mm) tall.
  • How long should I test for?
    A short-term test kit is ideal to find out what your Radon levels are right now, but it is not uncommon to have a four day spike or a four day lull in your Radon levels. As such, Health Canada recommends long-term testing (90+ day) to ensure that those spikes and lulls are evened out. However, we find that most people don't want to wait three months to find out if they are above the Action Levels.
  • How often should I test?
    Health Canada suggests that you retest your house every 5 years, or after any major renovations, just to ensure that nothing has changed.
  • My detector is still sealed in its package, can I still use it or did it expire?
    Long-term detectors should be used within 1 year of purchase to ensure that there are no environmental factors that may affect the readings. Our short-term e-perms have a shelf life of approximately two weeks once they arrive at your house.
  • When is the best time to test?
    Most homes have the highest levels of Radon gas during the winter. As such Health Canada recommends that you test then to ensure that you’re protected in a worst-case scenario.
  • Where should I place the detector in my home?
    The test kit should go in the lowest occupied level, or level that may be occupied at some point, for example, an unfinished basement. Health Canada recommends that you place the detector in the lowest area that you spend more than four hours a day in. If you don’t spend any time in the basement, then it should be placed in the lowest area that you do spend most of your time.
  • I have children, does that change where I put the detector?
    The lowest level where they, or anyone else spends any significant amount of time. Health Canada recommends that the test be done in the lowest level that may be occupied for more than four hours at a time. The test kits themselves should be placed in the breathing zone, so between you or your children’s head height while standing, to the height while sitting or lying down. If there is a nightstand, table, or shelf near the space they spend the most amount of time, that is ideal.
  • How many detectors or kits should I buy? Do I only test one room?
    For a residential setting, one detector is usually enough to be considered an accurate representation of the entire level. Especially large basement footprints (2000 sq ft+) may require an additional test kit to accurately cover the entire floor space.
  • I live in a rental building, should I still test for Radon?
    As Radon is a Class A Carcinogen, similar to Asbestos, its presence in a rental unit is the building owner’s/management's responsibility to fix. While it is uncommon for Radon to appear in higher levels of high-rise buildings, it is not impossible for it to happen, and converted residential buildings are subject to the same risks regular houses are.
  • I just moved in, is there a way to see if the previous residents tested the home?
    There is not currently a database of tests that have been completed. The best way to know if the building has been tested is to ask the previous occupants and/or landlords or owners.
  • Are there other homes in my community that have tested high?
    Whether or not they have been tested, there are very likely houses in your community that are above the Health Canada Action level of 200 Bq/m³. Radon is not restricted to only one or two locations geographically and can be present anywhere there are deposits of uranium or radium in the soil, and the amount can vary between close neighbours on the same street.
  • What is included in the price of the detector or kit?
    The test kit itself, detailed instructions, lab fees, a return package, and in the case of our short-term test kits, a prepaid return mailer from Canada Post
  • Is return shipping to the lab included?
    In our short-term test kit, yes. The long-term test kits go to a third party lab, and the test kits fit the size requirements of a regular letter.
  • I just received the detector, what do I do now?
    For short-term test kits; Close the windows and doors of your house, and wait for 12h (24 for post mitigation testing). Record the start time of the test kits on the instruction page, and open the canisters. Leave the test kits for 4 days. Close the canisters and record the end time. Place the canisters, and instruction page into the box it was shipped in (or provided for post mitigation tests), and secure the prepaid mailer to the front of the box. Send the box back to us via Canada Post. For long-term test kits; Login to the website in the second paragraph on the instructions page. You will need the Commission Number and Password at the top right hand side of the instruction page, as well as the serial number on the front of the test kit. It will ask you for your contact information and the start time for the test kit. Cut the package open, and leave the detector for 90 to 365 days. When you finish the test, put the detector in the pre-addressed envelope provided, login to the website again, update the end date, and send the test kit to the lab.
  • Where is my detector number?
    The long-term test kit’s detector number or serial number is the 9 digit code on the front of the detector. The short-term test kit’s detector number is on the bottom of the canister, on the blue label.
  • Will the detector still be reading while it is on its way to the lab? Does this affect my results?
    The test kits will still be reading some environmental or background radiation, and part of our quality assurance program is to do “blank” test kits to read this background radiation and adjust our results as required.
  • I've lost my detector or kit, will you send me another one?
    Unfortunately, we don't offer a replacement warranty should you lose your detector/kit. Please contact us via email or phone to order a replacement.
  • My pet ate the detector, should I be worried?
    The test kits themselves do not contain or trap radioactive materials. The devices housings and sensors are made of plastic, and the only metal component is a spring in the short-term test kit. In the event that this occurs, we do still recommend you consult your Veterinarian to ensure your pet’s health!
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