Last updated: 31 May 2026
A note before you read. This is general information for employers, building operators, and parents in Canada. It is not legal, occupational-health, or compliance advice. Radon obligations differ by jurisdiction and building type and are actively changing (see the 2027 federal change below) — confirm your specific duties with the relevant federal/provincial authority and a C-NRPP professional.
Quick answer
Radon is regulated more strictly in occupied buildings than many people realize. The Canadian reference level is 200 Bq/m³ (annual average). Federally regulated workplaces have a radon exposure limit under the Canada Occupational Health and Safety Regulations — historically 800 Bq/m³, now being harmonized down to 200 Bq/m³ (amendments published February 2026, coming into force February 2027). Provincial workplaces fall under each province's occupational-health rules. For schools and daycares, there's no national mandate, but several provinces have tested all public schools, and Yukon and B.C.'s Interior Health region require childcare facilities to test. Large buildings need a multi-detector protocol run by a C-NRPP professional; for a small office, home-based business, or in-home daycare, a long-term RadonTest.ca kit is an appropriate, low-cost starting point.
Table of contents
- Why occupied buildings differ from homes
- Workplaces — the federal rule (and the 2027 change)
- Workplaces — provincial OHS
- Schools
- Daycares & childcare
- How to test a building correctly
- Small office / in-home daycare — the simple option
- FAQ
- Sources & disclaimers
1. Why occupied buildings differ from homes
In a home, you place one detector in the lowest lived-in level. In a workplace, school, or daycare, people occupy many rooms across a larger footprint, so testing requires multiple detectors, placement in all frequently occupied ground-contact rooms, and documentation. The health logic is the same — radon is the leading cause of lung cancer in non-smokers — but the protocol and the duty of care are bigger. Health Canada recommends testing not just homes but all public buildings occupied for more than four hours a day, which includes workplaces, schools, and childcare centres.
2. Workplaces — the federal rule (and the 2027 change)
For federally regulated workplaces, the radon exposure limit lives in subsection 10.26(4) of the Canada Occupational Health and Safety Regulations (COHSR) under Part II of the Canada Labour Code.
- The long-standing limit was 800 Bq/m³ (annual average).
- Amendments published in the Canada Gazette in February 2026 lower this to 200 Bq/m³, to align with Health Canada's guideline. These come into force in February 2027.
- Nuclear energy workers are excluded (they're covered separately under the Nuclear Safety and Control Act).
In practice, a prudent federally regulated employer should already be testing to the 200 Bq/m³ target rather than waiting for the 2027 date.
3. Workplaces — provincial OHS
Most workplaces are provincially regulated and fall under each province's occupational health and safety legislation, which carries a general duty to protect workers from hazards (radon included). Specific radon provisions vary:
- Ontario publishes dedicated guidance on radon in the workplace.
- Several provinces reference Health Canada's 200 Bq/m³ guideline for below-grade and ground-floor work areas.
Either way, the prudent employer tests during the heating season with a long-term method and mitigates if results exceed 200 Bq/m³. Confirm your province's specific requirements.
4. Schools
There is no national legislation requiring radon testing in Canadian schools, but the federal government recommends it, and several jurisdictions have acted. Province-wide public-school radon testing has been completed in Nova Scotia, Prince Edward Island, New Brunswick, Saskatchewan, Quebec, and Yukon. Other provinces encourage testing but don't mandate it. Because children spend long hours in these buildings, the precautionary case is strong; school boards should test to a building protocol and re-test after major HVAC or building changes.
5. Daycares & childcare
This is where requirements are most concrete:
- Yukon requires radon testing in daycare centres.
- British Columbia's Interior Health region (Southeast B.C., including Kelowna) ordered licensed childcare facilities to test for radon (since 2017).
- Alberta introduced a Radon Awareness and Testing Act (Bill 209) that would have required childcare-facility testing at licensing/renewal, but it did not come into force — check Alberta's current status.
- Elsewhere, testing is recommended, not mandated, but Health Canada's "public buildings occupied >4 hours/day" guidance clearly includes childcare centres.
Operators should confirm their provincial childcare/education requirements and test to a building protocol — children are among the most important occupants to protect.
6. How to test a building correctly
- Use long-term (91+ day) measurement during the heating season — the same standard as homes, but with multiple detectors.
- Place detectors in all regularly occupied ground-contact and below-grade rooms.
- For anything beyond a very small space, engage a C-NRPP-certified measurement professional so the protocol and documentation stand up to scrutiny (and any future mitigation is defensible).
- Keep the lab reports on file; re-test after significant renovations or HVAC changes.
Need a professional for a larger building? Search the C-NRPP "Find a Professional" directory (you can filter for measurement vs. mitigation certification), or Take Action on Radon's find a measurement professional and find a mitigation professional listings. For a small space you can start yourself (below).
7. Small office / in-home daycare — the simple option
If you run a home-based business, a small single-room office, or an in-home daycare, a long-term test is a sensible first step:
RadonTest.ca ships a C-NRPP-approved long-term kit for $89, everything included (kit, shipping both ways, Canadian certified-lab analysis, plain-language result, English or French). For multiple rooms or larger sites, order multiple kits or use a C-NRPP professional. Order a kit »
8. FAQ
Is radon testing required in Canadian workplaces? Federally regulated workplaces have a radon exposure limit in subsection 10.26(4) of the Canada Occupational Health and Safety Regulations — historically 800 Bq/m³, being lowered to 200 Bq/m³ effective February 2027. Provincially regulated workplaces fall under provincial OHS rules, which carry a general duty to protect workers and often reference the 200 Bq/m³ guideline. Confirm your jurisdiction.
What is the radon limit for federally regulated workplaces? 200 Bq/m³ (annual average) once the February 2026 amendments take effect in February 2027 — down from the previous 800 Bq/m³. Nuclear energy workers are covered separately under the Nuclear Safety and Control Act.
Do schools and daycares have to test for radon in Canada? There's no national mandate. Province-wide school testing has been done in NS, PEI, NB, SK, QC, and Yukon. For childcare, Yukon and B.C.'s Interior Health region require testing; most other provinces recommend it. Check your provincial education/childcare authority.
Can I use a home radon kit for my workplace? For a very small space (a single-room office or in-home daycare), yes, as a start. Larger buildings need a multi-detector protocol, ideally run by a C-NRPP measurement professional.
What radon level requires action? The Canadian reference level is 200 Bq/m³ (annual average); above it, mitigate with a C-NRPP-certified professional.
How do I find a C-NRPP professional for my building? Search the official C-NRPP "Find a Professional" directory, which lets you filter by measurement vs. mitigation certification and by location.
9. Sources & disclaimers
Sources: Health Canada — radon guideline (200 Bq/m³); Canada Occupational Health and Safety Regulations, s.10.26; Employment and Social Development Canada — amendments to regulations under Part II of the Canada Labour Code (radon 800→200 Bq/m³, in force Feb 2027); Government of Ontario — Radon in the workplace; BC Lung Foundation — Radon in the workplace and Radon in daycares; C-NRPP "Find a Professional" directory.
Important disclaimers. Regulatory duties differ by jurisdiction, building type, and over time, and key rules are changing (notably the federal limit in February 2027); this article is a general overview as of 31 May 2026 and is not legal or compliance advice. Confirm obligations with the relevant authority and a C-NRPP professional before acting.
Testing a small office or in-home daycare? Start with a $89 all-in RadonTest.ca kit »