In Canada, the radon exposure limit for federally regulated workplaces drops from 800 Bq/m³ to 200 Bq/m³ on January 30, 2027. If your workplace is provincially regulated, that specific limit doesn't apply to you — but your employer still owes a general duty to protect workers from recognized hazards, and radon is one.
This guide is published by RadonTest.ca for workers, health and safety committee members, and health and safety representatives. It covers how to raise the question, what a proper test looks like, what the numbers mean, and what to do if the answer is unsatisfying. It is free to reproduce and circulate in your workplace, union or association — no permission needed.
The short version: Ask whether the building has been tested, in writing, through your committee. A proper test is long-term (3+ months, heating season), with a detector in every occupied ground-contact room — not one detector for the building. Health Canada recommends action above 200 Bq/m³. Records must be kept 30 years in federally regulated workplaces. Raise it through your committee first; if you are stonewalled, a federal worker can complain directly to the Labour Program.
Why this matters
Radon is a radioactive gas that seeps from the ground into buildings. You cannot see, smell or taste it at any concentration. It is the second leading cause of lung cancer in Canada after smoking, and the leading cause among people who have never smoked. Risk depends on concentration multiplied by time — and lung cancer from radon can take decades to appear, which is why a workplace exposure today matters long after the job ends.
Is your workplace covered by the new federal limit?
Yes if you work for: a chartered bank (not a credit union) · an airline or airport operation · a railway · an interprovincial trucking or bus company · marine shipping or a port · a pipeline · a telecom or broadcaster · Canada Post or a courier · a grain elevator or feed mill · a Crown corporation · a First Nations band council · the federal public service.
No if you work for: a provincial or municipal employer, a school board, a hospital, a university, a retailer, a manufacturer, a construction firm, a credit union, or a trucking company operating within one province. The general duty in your provincial legislation still applies.
Not sure? See which rules apply to your workplace.
Step 1 — Ask whether the building has been tested
This is the single most useful thing you can do. Put it in writing, through your joint health and safety committee, policy committee, or health and safety representative. Suggested wording:
"Has this building been tested for radon? If so, when, what were the results, and where are the records held? If not, what is the plan to test during the coming heating season?"
Once that question is asked and minuted, the hazard is identified and the employer knows. What happens next is the whole question — and in provincially regulated workplaces, failing to act on an identified hazard is exactly what general duty provisions exist to catch.
Step 2 — Know what a proper test looks like
Employers sometimes respond with a single detector, a short-term test, or a handheld reading. None of those meet Health Canada's method for workplaces. The Guide for Radon Measurements in Public Buildings requires:
- Long-term measurement — at least three months, during the heating season. Short-term measurements are explicitly not acceptable for deciding whether action is needed.
- A detector in every occupied room in contact with the ground — offices, work areas, classrooms — where someone spends more than four hours a day.
- One detector per 200 m² in rooms larger than 200 m².
- If the ground-contact level has no occupied rooms, every occupied room on the first occupied level above is tested.
- Quality control detectors on top — duplicates at 10% of locations, plus blanks.
- C-NRPP-approved devices, analyzed by an accredited laboratory.
A twelve-room ground floor needs roughly thirteen detectors, not one. If the employer reports a single number for a whole building, that is a reasonable thing to ask about.
Step 3 — Know what the numbers mean
| Result | What Health Canada recommends |
|---|---|
| Below 200 Bq/m³ | No further action required. Retest after major renovations or changes in ventilation or room use. |
| 200–600 Bq/m³ | Remediation within 2 years |
| Above 600 Bq/m³ | Remediation within 1 year |
There is no level considered risk-free. Health Canada advises that building owners still consider mitigation where results approach but do not exceed the guideline.
Step 4 — Make sure it's recorded
The regulations already require the qualified person's hazard investigation report to be kept 30 years from the date it was signed (s. 10.6); the 2026 amendments extend air sampling record retention to match. Results, detector locations, dates and follow-up actions belong in the workplace's records — not in one manager's inbox. A worker diagnosed in 2050 will depend on records created today.
What a proper record looks like
If your employer says the building was tested, the record should contain, for each test: the date, time and location; the substance tested for; the sampling and testing method; the result; and the name and occupation of the person who made the test.
A one-page laboratory certificate with a number on it is not a complete record. If the committee asks to see the results and receives only a lab report, asking where the placement locations, dates and method are documented is a reasonable follow-up.
Step 5 — If you get no answer, know the escalation route
Start with your committee. In almost every case, a question raised and minuted through the joint health and safety committee, policy committee, or health and safety representative is what gets a building tested. Give the employer a reasonable opportunity to respond — most will, and a cooperative process produces a better result than an adversarial one.
If the question is ignored or stonewalled, there is a further route. In a federally regulated workplace, a worker is not required to raise the matter with the employer first: a complaint may be made directly to the Labour Program of Employment and Social Development Canada. It can prompt an inspection and can become part of the public record. The Labour Program may also inspect and audit on its own initiative, issue compliance orders, and levy administrative monetary penalties.
In a provincially regulated workplace, the equivalent route is your provincial occupational health and safety regulator, with the general duty clause as the basis.
The order matters. Raise it through the committee, document the request and the response, and escalate only if you get nowhere. An employer given a fair chance to act usually acts.
There is more to the file than results: the qualified person's signed report, the employer's written control procedure (which must be available to you), and the education and training records. See what a compliant radon record contains.
Questions for your committee's agenda
- Has this building been tested for radon? When, and by what method?
- How many detectors were used, and in which rooms?
- Was the test at least three months, during the heating season?
- Were the detectors C-NRPP-approved and laboratory-analyzed?
- Where are the results filed, and can the committee see them — including placement locations, dates, method and who performed the test?
- If the building has never been tested, when will detectors be placed?
- If a previous result was above 200 Bq/m³, what was done, and was it retested afterward?
- Does the employer's testing cover every building we occupy, including leased space?
If your employer says the portfolio is too large to test
That may be true, and there is a recognized answer for it. 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, provided the employer raises it with and agrees it with the regulator.
So the committee question isn't "why haven't you tested everything?" It's: which buildings are prioritized, what is the schedule, and has this been discussed with the Labour Program? An employer with a written plan is in a very different position from one with nothing.
Why this fall matters
The regulation contains no deadline to test. But the duty begins January 30, 2027 and is defined as an annual average, which requires at least 91 days of measurement during the heating season.
Counting 91 days back from January 30, 2027 lands in early November 2026. And detectors placed after the end of January push the test period outside the heating season, which undermines the result — so the usable deployment window runs October 1 to the end of January.
That's not a legal deadline. It's arithmetic, and it's why the question is worth raising at your next committee meeting rather than in the new year. The full timing explanation is here.
Common questions
Can I ask my employer to test for radon?
Yes. The natural route is your joint health and safety committee or health and safety representative. Put the request in writing so it is minuted.
What if my employer refuses?
Raise it through your committee first and document the request. If it is ignored or refused without explanation, a federally regulated worker may complain directly to the Labour Program; in a provincially regulated workplace, your provincial occupational health and safety regulator is the equivalent route, with the general duty clause as the basis.
Is one detector enough for our building?
Almost certainly not. Health Canada's workplace protocol calls for a detector in every occupied room in ground contact, plus one per 200 m² in larger rooms, plus quality-control detectors.
Can I use a consumer radon monitor at my desk?
It will tell you something about your own area, but it does not meet the method for establishing an annual average, and it is not a substitute for the employer's obligation. Health Canada's guide states short-term measurements are not acceptable for deciding whether remediation is needed.
What if I only work there part-time?
The measurement protocol tests rooms occupied more than four hours a day. Exposure risk is cumulative, so less time means less exposure — but the building-level obligation is unchanged.
Read next
The new federal limit explained · Which rules apply to your workplace · Workplace radon FAQ · The legal brief · Canada radon map
About this guide. Published by RadonTest.ca, Canada's independent radon testing service. We supply C-NRPP-approved test kits and accredited laboratory analysis across Canada, in English and French. We do not perform radon mitigation, and we earn nothing from what your result says — which is why we can write a guide like this one.
Free to reproduce and circulate within your workplace, union or association. No permission needed — please keep the RadonTest.ca attribution and the link to radontest.ca so readers can find the current version.
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 is general information for workers and health and safety committees and is not legal advice.
Sources
Canada Labour Code, Part II; Canada Gazette, Part II, Vol. 160, No. 3 (SOR/2026-10); Canada Occupational Health and Safety Regulations, ss. 10.3 and 10.26(4) as amended; Health Canada, Guide for Radon Measurements in Public Buildings; Health Canada, Canadian radon guideline; CCOHS, Radon in Buildings.