About 1 in 5 Canadian homes has a radon level above Health Canada's guideline, per the 2024 cross-Canada radon survey — and more than 90% of Canadian homeowners have never tested. Testing is the only way to know your home's level: radon varies widely even between neighbouring houses on the same street. Here's how to test the way Health Canada actually specifies — and which kind of test to buy.
What Health Canada's Testing Protocol Requires
- Long-term means at least 91 days. Health Canada defines a long-term test as 91+ days and recommends testing over 3 to 12 months. Short-term results (under 91 days) are not appropriate for making mitigation decisions.
- Test during the heating season. The current guidance: a minimum of 91 days of the test should fall within the heating season. Winter readings run higher (closed windows, stack effect), so heating-season tests give a conservative — protective — estimate. A below-guideline result from a test that missed the heating season should be re-done the next fall/winter.
- Location matters. Place the detector in a normal occupancy area (somewhere someone spends 4+ hours a day) on the lowest lived-in level — not the kitchen, bathroom, or laundry room — in the breathing zone, away from heat sources, sunlight, drafts, and exterior walls. Then live normally for the duration.
The number that matters is 200 Bq/m³ — the Canadian guideline, applied to your average annual level. There's no risk-free level; if your long-term average is above 200 Bq/m³, Health Canada recommends corrective action within 1 year, sooner for higher levels. Radon is the leading cause of lung cancer after smoking in Canada, responsible for more than 3,000 lung cancer deaths a year and an estimated 16% of lung cancer deaths — and it's the number one cause in non-smokers.
Your Two Ways to Test
Long-term alpha track test kit — the lab-documented number
An alpha track detector is a small passive device: a filter-covered chamber admits radon gas while excluding its decay products, and alpha particles from radon decay leave microscopic tracks in a special plastic inside. After your 91+ days, you mail it to the laboratory, the tracks are counted, and you receive your average radon level. No power, no batteries, no readings to interpret — alpha track detectors are one of the two passive device types Health Canada recommends, and the common format of mail-in DIY test kits. Health Canada recommends devices that have passed C-NRPP performance testing — which is exactly what our Radtrak³ long-term alpha track kit ($60, lab analysis included) is. This is the test format for grant applications (the Lungs Matter grant, administered by the Canadian Lung Association, requires long-term results — minimum 90 days — from a C-NRPP certified test kit) and it gives you an independent, lab-documented result for your mitigation decision and real estate paperwork. Testing multiple properties? The kit is available in 10, 25, and 100-packs at volume pricing.
Digital radon monitor — the continuous picture
Electronic radon monitors (like the Airthings line and RadonEye RD200) continuously measure and display radon on-screen or in an app. Health Canada accepts C-NRPP-listed electronic monitors for long-term measurement — they're the only active devices it recommends for the job — with two caveats worth knowing before you rely on one for an official number: compare only the long-term average (not daily spikes) to the 200 Bq/m³ guideline, and Health Canada recommends considering replacement five years after purchase unless the unit can be recalibrated — many consumer models can't, and C-NRPP doesn't approve consumer-grade monitors for professional use. Where monitors shine: watching seasonal patterns, verifying your mitigation system keeps working year after year, and instant feedback after changes.
Which should you buy?
- You want an independent, lab-documented result (grant applications, real estate paperwork, or simply a number analyzed by someone other than the device on your shelf): the lab-analyzed long-term kit. A C-NRPP-listed monitor's 91+ day average is equally valid for the decision itself.
- You want ongoing awareness (especially after mitigation): a digital monitor.
- The thorough answer is both: a $60 lab test for the decision, a monitor for the years after. Health Canada pegs DIY long-term kits at typically $30–$60; professional C-NRPP measurement services are also available at higher cost — find a certified professional here.
Where Levels Run Highest
Health Canada's 2012 Cross-Canada Survey (almost 14,000 homes, long-term tests) found 6.9% of Canadians living above the guideline nationally — with Manitoba, New Brunswick, Saskatchewan, and the Yukon showing the highest percentages, and 14 health regions where 23–44% of homes tested high. Newer surveying pushed the national estimate to about 1 in 5 homes, with more than 40% of homes above the guideline in parts of New Brunswick and Manitoba and over half in some cities such as Castlegar, BC and Regina, SK. But the survey data's real lesson is Health Canada's own: every home should be tested, no matter where it is — your neighbour's result says little about yours. See your region's picture on our radon by city pages or the province-by-province data.
After the Test
- Below 200 Bq/m³: C-NRPP's homeowner guidance is to retest within 5 years, or after major renovations.
- Above 200 Bq/m³: act within a year. Health Canada recommends a C-NRPP certified mitigation professional; a system typically installs in under a day and cuts levels by more than 80% in most homes. Handy homeowners can read our DIY mitigation guide and see the real cost breakdown.
- After mitigation: verify — a short-term check by a certified professional starting at least 24 hours after the fan comes on, then a long-term measurement within two years of activation and at five-year intervals afterwards.
Frequently Asked Questions
- How long should a radon test run in Canada?
- At least 91 days — Health Canada's definition of a long-term test — with a minimum of 91 days falling within the heating season. Results from shorter tests aren't appropriate for mitigation decisions.
- Are digital radon monitors accepted by Health Canada?
- Yes, for long-term measurement — provided the monitor has passed C-NRPP performance testing and you compare the long-term average (not short-term readings) to the 200 Bq/m³ guideline. Health Canada also recommends considering replacement five years after purchase unless the unit can be recalibrated.
- Where should I place a radon test kit?
- In a normal occupancy area of the lowest lived-in level — a room where someone spends 4+ hours a day, not the kitchen, bathroom, or laundry — in the breathing zone, away from heat, sunlight, drafts, and exterior walls, per Health Canada's measurement guide.
- What if my radon level is above 200 Bq/m³?
- Health Canada recommends corrective action within 1 year — sooner the higher the level. A radon mitigation system reduces radon by more than 80% in most homes, per Health Canada, and grants like Lungs Matter (up to $1,500, administered by the Canadian Lung Association) require exactly the long-term C-NRPP test result you now have.
Sources
- Health Canada — Guide for Radon Measurements in Homes (91-day definition, heating-season requirement, placement, device types, ERM guidance)
- Government of Canada — Radon Guideline (200 Bq/m³, 1-year action timeline)
- Health Canada — Testing Your Home (two testing options, ERM acceptance)
- Health Canada — Radon Action Guides (1 in 5 homes, kit pricing, regional data, deaths and 16%)
- Health Canada — 2012 Cross-Canada Survey (6.9%, highest jurisdictions)
- C-NRPP — Consumer-Grade Electronic Radon Monitors (calibration limits, 3-month guidance)
