In Canada, workplace radon rules changed with SOR/2026-10: from January 30, 2027, federally regulated employers must ensure no employee's exposure averages more than 200 Bq/m³ over a year. These are the questions employers, health and safety committees and employees ask most — answered plainly, with each answer standing on its own.
TL;DR: Federally regulated employers must ensure no employee is exposed to an annual average above 200 Bq/m³ from 30 January 2027. Provincially regulated employers have no radon-specific number but owe a general duty. The recognised measurement is a long-term test of at least three months during the heating season, with a detector in every occupied ground-contact room. There is no test-by date in the regulation — the timing follows from the annual-average metric.
1. Does my employer have to test for radon in Canada?
If the employer is federally regulated, effectively yes: from January 30, 2027 the employer must ensure no employee's annual-average radon exposure exceeds 200 Bq/m³, and an employer cannot ensure an annual average it has never measured. If the employer is provincially regulated, no specific radon limit applies, but every provincial OHS act imposes a general duty to protect workers from recognized hazards — and radon is one.
2. What is the radon limit for workplaces in Canada?
For federally regulated workplaces: 200 Bq/m³ as an annual average, effective January 30, 2027, under the amended Canada Occupational Health and Safety Regulations. Until that date the previous limit of 800 Bq/m³ remains in force. Health Canada's guideline of 200 Bq/m³ applies as guidance to all indoor spaces, including provincially regulated workplaces.
3. When does the new workplace radon limit take effect?
January 30, 2027 — the first anniversary of the regulation's registration, as set by section 77(1) of SOR/2026-10.
4. What is SOR/2026-10?
A federal regulation registered January 30, 2026 and published in the Canada Gazette, Part II on February 11, 2026, amending five occupational health and safety regulations under the Canada Labour Code. Among other changes, it lowers the workplace radon exposure limit from 800 to 200 Bq/m³ and adds new requirements for nanomaterials, thermal stress and UV radiation.
5. What was the old workplace radon limit?
800 Bq/m³ — four times Health Canada's residential guideline. The gap existed because the workplace regulation was never updated after Health Canada lowered its guideline to 200 Bq/m³ in 2007. SOR/2026-10 closes it.
6. Who enforces workplace radon rules in Canada?
For federally regulated workplaces, the Labour Program of Employment and Social Development Canada enforces Part II of the Canada Labour Code. Health Canada provides the science and guidance but is not the workplace enforcer. Provincially regulated workplaces answer to their provincial OHS regulator (for example, CNESST in Quebec or WorkSafeBC in British Columbia).
7. Does the new radon limit apply to all Canadian businesses?
No — only to federally regulated employers, about 8% of the workforce: banking, interprovincial and international transport, pipelines, telecommunications and broadcasting, postal and courier services, grain handling, Crown corporations, First Nations band councils, and the federal public administration. Everyone else falls under provincial law.
8. Is my bank, trucking company or radio station covered?
A chartered bank: yes. A credit union: no (provincial). A trucking company whose vehicles cross provincial or national borders: yes, including its terminals and offices. A purely local carrier: no. A radio or television broadcaster: yes. The full list, with the confusing cases, is in our guide: Is my workplace federally regulated?
9. Do First Nations band councils have to comply?
Yes. Band councils are federally regulated employers under the Canada Labour Code, so band offices, band-operated schools and community buildings are covered by the 200 Bq/m³ limit — a significant point, since many are located in regions where a high share of buildings test above the guideline.
9b. Where can band councils find more detail?
We have a dedicated guide covering which band-operated buildings are affected, why regional geology matters, the testing method and the timing: radon and the federal workplace limit for band councils.
10. Are nuclear workers covered?
No. Nuclear energy workers, as defined in the Nuclear Safety and Control Act, are expressly excluded — they are protected under a separate radiation regime administered by the Canadian Nuclear Safety Commission.
11. Is there a deadline to test for radon at work?
The regulation contains no test-by date. But the duty takes effect January 30, 2027 and is defined as an annual average, and the recognized measurement is a long-term test of at least 91 days. Counting 91 days back from January 30, 2027 lands in early November 2026 — which is why fall 2026 is the practical measurement window, even though no statute names it.
12. How is workplace radon measured? Is it the same as testing a house?
No — workplaces follow a different protocol. Health Canada's Guide for Radon Measurements in Public Buildings (which explicitly covers workplaces) requires long-term detectors in every occupied room with floors or walls in contact with the ground — an "occupied room" being one where someone spends more than four hours a day — with one detector per 200 m² in larger rooms, for a minimum of three months during the heating season. A house takes one detector; a workplace takes as many as its floor plan requires. The guide also adds quality-control detectors on top: duplicate detectors at 10% of locations, plus blanks.
13. How long does a workplace radon test take?
A minimum of 91 days of passive measurement, plus laboratory analysis time after the detectors are retrieved. The work is almost entirely waiting: placement takes minutes per location, and nothing needs attention during the test period.
14. How many radon detectors does an office or workplace need?
Count the occupied rooms in ground contact — that number is your starting detector count. Under Health Canada's Guide for Radon Measurements in Public Buildings: one detector in each occupied room with floors or walls touching the ground or a crawl space; one detector per 200 m² (2,153 ft²) in rooms larger than 200 m²; and if the ground-contact level has no occupied rooms, every occupied room on the first occupied level above is tested until the building footprint is covered. An "occupied room" is one where a person spends more than four hours a day, and a room subdivided by cubicle partitions counts as one room, not many.
Quality control is added on top of that count: duplicate detectors at 10% of measurement locations (two placed side by side, no more than 10 cm apart, capped at 25 duplicates per month), plus roughly 5% blanks. The first detector deployed should be a duplicate; the rest are distributed randomly through the deployment. A building needing 20 detectors by floor plan therefore needs roughly 23 once QC is included. (Spikes — detectors exposed to a known concentration in an accredited chamber — are a laboratory quality-control step, not detectors placed in your building.) Bathrooms, kitchens, storage areas and indoor parking levels are excluded — no detector required there. Placement: 0.5–2 m from the floor, at least 30 cm from an exterior wall, 10 cm clear of surrounding objects, away from HVAC air currents, heat sources and direct sunlight.
15. What happens if a workplace tests over 200 Bq/m³?
Health Canada recommends remedial action — the higher the level, the sooner — carried out by certified radon mitigation professionals (C-NRPP), followed by retesting to confirm the reduction. Mitigation for most buildings is an established, well-understood fix. All health guidance on radon is Health Canada's; canada.ca/radon is the authoritative source.
15b. Our result came back just under 200 — are we finished?
Legally, a result below 200 Bq/m³ means no action is required. Practically, a result in the 150–200 range deserves a second look, for three reasons.
First, 200 is an action level, not a safety threshold — there is no radon concentration considered risk-free, and Health Canada advises that building owners consider mitigation even where results approach the guideline without exceeding it. Second, radon varies year to year with weather, ground conditions and how the building is operated; a building at 180 this year can be above 200 next year with nothing having changed. Third, every measurement carries uncertainty — a reported result near the guideline sits within a range, and part of that range may be above it.
Common industry practice is to treat 150–200 Bq/m³ as a watch band: retest, and monitor the building rather than closing the file. That is prudent practice rather than a regulatory requirement, but it is a defensible position and an easy one to document. Full detail, including the 50 per cent criterion in the regulations: our result came back at 180 — are we finished?
15c. Who should perform the test after mitigation?
Health Canada recommends it not be the installer: "to avoid conflict of interest, the test should not be performed by the company that installed the radon mitigation system." That guidance is residential — no workplace-specific verification standard exists in Canada — but the reasoning transfers. The sequence is a short-term test at least 24 hours after the fan is activated, a long-term test of at least three months during the following heating season, and retesting at least every five years. That interval comes from Health Canada's residential guidance; the public-buildings guide sets no post-mitigation retest interval, so it is applied to workplaces by extension rather than by rule. See post-mitigation radon verification.
16. Can employees ask for radon testing at work?
Yes. The natural route is the workplace health and safety committee or health and safety representative — the same bodies the amended regulations involve in hazard procedures. An employee, committee member or union representative can table radon as a workplace hazard question and ask what measurement the employer has done or plans. We publish a free guide for workers and committees covering exactly how to raise it.
17. What records must employers keep?
The amendments set a qualified person's hazard investigation report to be kept 30 years from the date it was signed (s. 10.6 of the Canada Occupational Health and Safety Regulations, already in force), and extend air sampling record retention to match. Radon measurement results, dates, locations and follow-up actions belong in records built to that horizon.
18. Does this apply in Quebec?
Federally regulated workplaces in Quebec — banks, telecoms, interprovincial carriers, federal offices — yes, exactly as elsewhere. Provincially regulated Quebec workplaces fall under the CNESST regime instead, which we cover in our Quebec employer guide.
19. What about schools and daycares?
Most schools and daycares are provincially or territorially regulated, so the federal limit doesn't bind them directly — the notable exception being band-operated schools and childcare, which are federal. Health Canada's public-buildings measurement guide explicitly covers schools and day cares, and health and childcare advocacy organizations have pushed for childcare-specific testing policy on the grounds that children breathe more air relative to body weight and accumulate risk over more years of life. Provincial policy varies and continues to evolve; our schools and daycares guide covers the landscape.
20. Do short-term tests or consumer radon monitors satisfy the limit?
The limit is an annual average, and Health Canada's public-buildings guide states that short-term measurements are not acceptable for determining whether remediation is needed. Long-term measurement — three months or more, during the heating season — is what establishes an annual average. Continuous radon monitors have a specific supplementary role in buildings where ventilation differs sharply between occupied and unoccupied hours, but they follow a long-term test rather than replacing it.
21. What if radon levels are only high when the building is empty?
This is common in buildings whose ventilation shuts down after hours, and Health Canada's guide provides a specific method for it: after a long-term test comes back above the guideline, a seven-day continuous-monitor test during the heating season can establish the ratio between occupied-hours and overall average concentrations, which is then applied to the long-term result to estimate occupied-hours exposure. The guide cautions that this estimate is approximate, should only be used where the difference is significant, and should not be used at all if the monitor shows levels above the guideline during occupied hours.
22. How often does a workplace need to be retested?
Health Canada's public-buildings guide does not set a fixed retest interval for buildings that tested below the guideline. The trigger is change, not the calendar. Retesting is indicated when:
- the building undergoes major renovation
- ventilation or HVAC systems are modified, upgraded or rebalanced
- airflow through the building changes for any reason, including energy retrofits and air sealing — C-NRPP notes that work making a building more airtight is likely to increase indoor radon
- occupancy or the use of rooms changes, particularly on the lowest occupied level — a storage room converted to offices is a new measurement question
- anything changes in how the building meets the surrounding soil
Where a change triggers a retest, the measurement is a three-month test during the first heating season after the work is finished.
Two things sit outside that rule. After mitigation, a short-term test confirms the immediate reduction, a long-term test during the next heating season confirms it holds, and retesting every five years thereafter confirms levels stay low. That interval comes from Health Canada's residential guidance; the public-buildings guide sets no post-mitigation retest interval, so it is applied to workplaces by extension rather than by rule. And as a matter of practice rather than regulation, many organisations adopt a periodic review interval anyway — commonly around ten years — on the reasoning that foundations age, seals degrade and HVAC systems become less efficient in ways nobody formally records as a "change." Neither Health Canada's guidance nor the Canada Labour Code specifies such an interval; it is prudent practice, not a requirement.
23. We lease our space — is radon our responsibility or the landlord's?
Under the amended wording, the federally regulated employer is the named duty holder: the employer must ensure. The previous "no employee shall be exposed" left room for tenant and building owner to each point at the other; the new text does not. That said, radon enters through the foundation and moves through the whole structure, so testing only your own suite can produce a reassuring number that says nothing about the rest of the building — Health Canada's guidance is to test a building in its entirety. The practical step is to raise it with the property manager early and check what your lease says. Whether duties also fall on the landlord depends on that agreement, and that is a question for your legal advisor.
24. What if we have hundreds of untested buildings and can't test them all in one season?
The Labour Program has acknowledged that testing a large untested portfolio by the in-force date may not be realistic, and that a phased approach — highest-risk buildings first, with documented prioritization and a written plan for the rest — can be a recognized path forward. It is not automatic and not guaranteed: it has to be raised with the regulator, explained and agreed, and the changes have been public since 2023. What separates an employer working toward compliance from one that is non-compliant is documented intent — a written prioritization, a testing schedule, and evidence that testing has started.
25. Can a worker report radon directly to the regulator?
Yes. In federally regulated workplaces a worker is not required to go to the employer first — a complaint can go straight to the Labour Program, can trigger an inspection, and can become part of the public record. The Labour Program can also inspect and audit on its own initiative, issue compliance orders, and levy administrative monetary penalties.
26. Where can I read the official regulation?
SOR/2026-10 is published in the Canada Gazette, Part II, Volume 160, Number 3 (February 11, 2026), at gazette.gc.ca. The consolidated Canada Occupational Health and Safety Regulations, including the amended section 10.26, are on the Justice Laws website. Employment and Social Development Canada also publishes a plain-language overview of the amendments to regulations under Part II of the Canada Labour Code.
27. What penalties exist for non-compliance?
Part II of the Canada Labour Code carries the Labour Program's compliance and enforcement tools, and the SOR/2026-10 package made consequential amendments to the Administrative Monetary Penalties (Canada Labour Code) Regulations, so violations of the amended provisions can attract administrative monetary penalties. Amounts depend on the violation type and the employer.
RadonTest.ca provides testing logistics and laboratory submission. We do not perform radon mitigation and we do not interpret health risk — Health Canada is the health authority on radon in Canada. This page describes publicly available regulatory information and is not legal advice.
Sources
Canada Gazette, Part II, Vol. 160, No. 3 (SOR/2026-10) and accompanying Regulatory Impact Analysis Statement; Canada Occupational Health and Safety Regulations, s. 10.26(4) as amended; Employment and Social Development Canada, Introducing amendments to regulations under Part II of the Canada Labour Code; Health Canada, Guide for Radon Measurements in Public Buildings (H129-120/2022E); Health Canada, Canadian radon guideline; CCOHS, Radon in Buildings; C-NRPP Quality Control and Quality Assurance Manual.
Read next
SOR/2026-10 explained · Is my workplace federally regulated? · The compliance timeline · Commercial radon testing: process and cost · Quebec workplaces (CNESST) · Schools and daycares