Radon Test Results Explained: What Bq/m³ and pCi/L Mean
By First Choice Radon · Updated October 14, 2026 · 8 min read
You have a radon number, and now you need to know what it means. This guide explains the units, Health Canada’s 200 Bq/m³ guideline, what to do at each level, and what a trustworthy test report includes.
Bq/m³ is Health Canada’s guideline. That equals 5.4 pCi/L.
Multiply pCi/L by 37 to convert it to Bq/m³.
Health Canada’s timeline to reduce radon at or above 200 Bq/m³.
Bq/m³ and pCi/L: what the units mean
Radon is measured by how much radioactivity is in the air. In Canada, results are reported in becquerels per cubic metre (Bq/m³). One becquerel is one radioactive breakdown per second, so Bq/m³ counts breakdowns in each cubic metre of air.
Some devices and U.S. reports use picocuries per litre (pCi/L). To convert, multiply pCi/L by 37 to get Bq/m³, or divide Bq/m³ by 37 to get pCi/L.
| Bq/m³ | pCi/L | How it compares |
|---|---|---|
| 100 | 2.7 | The World Health Organization’s suggested reference level |
| 200 | 5.4 | Health Canada’s guideline |
| 400 | 10.8 | Twice the guideline |
| 1,000 | 27.0 | Five times the guideline |
Health Canada’s 200 Bq/m³ guideline
Health Canada’s guideline for indoor radon is 200 Bq/m³ (5.4 pCi/L), measured as a long-term average over at least 91 days. A long test matters because radon rises and falls from day to day with weather and air pressure, and a short test can miss your real average.
The guideline is not a line between safe and dangerous. Radon risk builds with long-term exposure, so a lower number is always better, even below 200.
The World Health Organization suggests a lower reference level of 100 Bq/m³. Canada’s guideline is 200, and Health Canada recommends reducing radon in any building at or above it.
What to do at each level
Below 200 Bq/m³
No action is required. Any reduction still lowers risk, and levels can change if the building changes, so keep the report and retest after major renovations or foundation work.
200 Bq/m³ or more
Health Canada recommends reducing radon within one year. A C-NRPP certified professional can assess the building and give a written mitigation quote.
Much higher than 200
Act sooner. Health Canada advises faster action as the number climbs. A high result is not an emergency, because risk builds over years, but it should not wait.
After mitigation
Health Canada advises retesting after a system is installed to confirm the level has dropped, then again every five years. In most homes a system can reduce radon by up to 95%.
What a good radon test report includes
A report you can rely on should make the test easy to verify. Look for:
- The result in Bq/m³, with pCi/L if relevant.
- Start and end dates, showing the test ran at least 91 days.
- The detector location, described clearly. Detectors are normally placed at the lowest level of the building, at least 30 cm above the floor, 30 cm from exterior walls, and about 1 m from windows, doors and vents.
- The tester’s C-NRPP certification. Health Canada recommends using certified professionals.
- Plain-language next steps, so you know what the number means for you.
At First Choice Radon, every 91-day test is $99 and includes set-up, pick-up and your result explained.
Short-term vs long-term results
A short-term test lasts a few days and gives a snapshot. It can be useful when time is tight, for example during a property sale, but it cannot show your true average. Treat a short-term number as a prompt to run a 91-day test, not as the final answer.
A long-term test is the one used to decide whether mitigation is needed, because it averages out day-to-day swings.
Radon test results questions
What is a high radon level in Canada?
Health Canada’s guideline is 200 Bq/m³ (5.4 pCi/L). At or above that long-term average, Health Canada recommends reducing radon within one year, and sooner if the level is higher.
What does Bq/m³ mean on a radon test?
Bq/m³ stands for becquerels per cubic metre. A becquerel is one radioactive breakdown per second, so the unit counts breakdowns in each cubic metre of air.
How do I convert pCi/L to Bq/m³?
Multiply pCi/L by 37. For example, 5.4 pCi/L equals about 200 Bq/m³. To go the other way, divide Bq/m³ by 37.
Is 100 Bq/m³ a safe radon level?
Radon has no completely risk-free level. 100 Bq/m³ is below Health Canada’s guideline of 200, so no action is required, though lower is always better. The World Health Organization suggests 100 as a reference level.
How long should a radon test run?
At least 91 days. Radon changes from day to day, and a long test averages those changes. Short-term tests are only a snapshot.
What should I do if my result is above 200 Bq/m³?
Plan to reduce radon within a year, or sooner if the level is much higher. A C-NRPP certified professional can assess the building, quote the work in writing and retest afterward.
When should I test for radon again?
Health Canada advises retesting after a mitigation system is installed and every five years after that. It is also worth testing again after major renovations or foundation work.
Get your radon number
A 91-day test is $99 and includes set-up, pick-up and your result explained. Serving Cochrane, Calgary and surrounding Alberta communities. See our pages for Calgary, Cochrane, Okotoks, Airdrie.
Sources: Health Canada: Radon; Health Canada: Radon in real estate; WHO Handbook on Indoor Radon; Cross-Canada Survey of Radon, 2024.
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