How to Test Your Home for Radon in Canada

Radon is a radioactive gas that can seep into a home from the ground, and you can’t see or smell it. Testing is the only way to know your level. Here’s what Health Canada says about how to test, where to put the monitor, and three monitors to consider if you’d rather read the result yourself.

How Health Canada says to test

• Use a long-term test: leave a long-term detector or an electronic monitor in place for at least 3 months (up to 12 months is fine).
• The 200 Bq/m³ line: if your radon level is 200 Bq/m³ or higher, take action to reduce it within 1 year.
• Test the lowest floor you actually use, such as a family room, a bedroom, a playroom or a finished basement.
• If you use an electronic monitor, choose one that has passed C-NRPP performance testing. You can read results on the device or in its app.

Sources: Health Canada, How to test your home for radon and Health Canada, Radon gas in your home. Model details come from the listings, so check the product page before you order.

Where to put the monitor

Health Canada’s instructions are specific about placement:

• Put it at breathing height, 0.5 to 2 metres from the floor, on a table, shelf or desk, or hung from a wall or ceiling.
• Skip kitchens, bathrooms, laundry rooms, closets and unfinished basements.
• Keep it away from windows, doors, vents and exterior walls, from heat sources such as fireplaces and direct sunlight, and from a TV, fridge or microwave.

When to test, and why 3 months

Radon levels move up and down, so a quick reading can mislead you. C-NRPP, Canada’s radon proficiency program, says to leave a monitor in place for at least 3 months, preferably during the heating season when indoor radon levels are typically highest. If you check a digital monitor for less than 91 days, follow up with a long-term test, and base any decision on the long-term average. Each device calculates that average differently, so read the manufacturer’s guide to find it (C-NRPP consumer monitor report).

What the numbers mean in Alberta

Radon levels can’t be predicted for a given home. In Health Canada’s 2012 Cross-Canada Survey, 7% of Alberta homes measured above the 200 Bq/m³ guideline, and Take Action on Radon notes that testing in some areas has found more than half of homes above it. Its advice is simple: every home needs to test (Take Action on Radon, Alberta).

Which monitor to buy

Not every radon monitor sold online is a good one. C-NRPP’s 2025 consumer report lists Airthings Corentium Home, Airthings View, Aranet RN+, Ecosense EcoQube, Ecosense RadonEye and SunRadon Luft as approved. It also lists a number of other consumer monitors as not approved, and Health Canada has recalled some of them. If a monitor isn’t on that list, check it against the report before you buy (full list).

These monitors cannot be professionally calibrated and are not approved for use by radon measurement professionals, so treat them as a way to find out whether you need to take the next step.

If your result is high

1. Don’t panic over a short-term spike. If a short-term reading is over 200 Bq/m³, run a long-term test before deciding on repairs.
2. If your long-term level is 200 Bq/m³ or higher, plan to reduce it within a year.
3. Hire a C-NRPP certified radon mitigation professional to choose the method.
4. Test again after the work is done to confirm the level has dropped.

Source: Windsor-Essex County Health Unit, Information about radon testing and Health Canada.

Related guides

• How to Choose a Carbon Monoxide Alarm in Canada
• How to Choose a Basement Dehumidifier in Canada
• How to Size an Air Purifier the Health Canada Way