Children spend around 1,200 hours a year in a school building, and younger children spend most of that time on the lowest floors. If you have started wondering whether anyone has measured the radon in that building, this sets out how to find out and what to do with the answer.
Two things worth saying at the start. Most buildings test below the guideline — the likeliest outcome of asking is a reassuring answer. And a school that has not tested is not unusual or negligent; almost no Canadian jurisdiction requires it, and the great majority of schools have never been measured.
The short version. Ask the principal or the board's facilities department in writing whether the school has been tested, when, and what the results were. No province requires school radon testing, so this is a request rather than an enforcement matter — but Health Canada's 200 Bq/m³ guideline applies to all indoor spaces, and school boards have a general duty to their staff which reaches the same buildings. A proper test is long-term, at least three months during the heating season, with a detector in each occupied ground-floor room.
What actually applies to schools
Being accurate here matters, because a request based on a rule that does not exist is easy to dismiss.
No Canadian province or territory requires radon testing in schools. There is no federal requirement either, except for schools operated by a First Nations band council, which are federally regulated as workplaces.
What does apply:
- Health Canada's guideline of 200 Bq/m³ applies to all indoor spaces, including schools. It is a guideline rather than a regulation, and Health Canada publishes a specific measurement protocol for public buildings including schools.
- Occupational health and safety law reaches the same building through a different door. Teachers and staff are workers, school boards are employers, and every jurisdiction imposes a general duty to take reasonable precautions against recognised hazards. The building does not get tested for students and not for staff — it is one measurement.
- One regional exception: in British Columbia, Interior Health ordered radon testing in licensed childcare facilities within its region, using a medical health officer's authority. That is regional and applies to childcare rather than schools generally.
- Alberta passed a Radon Awareness and Testing Act in 2017 that would have applied to childcare facilities. It was never proclaimed into force and lapsed in 2023. There is no Alberta requirement.
So the honest framing when you ask is: nobody is obliged to do this, and it is reasonable to ask anyway.
First, check whether your province has already done it
This is the step most people skip, and in six jurisdictions it produces the answer immediately.
Health Canada's radon action guide for provinces and territories records that all public schools have been tested in Nova Scotia, Prince Edward Island, New Brunswick, Saskatchewan, Quebec and Yukon. In British Columbia, Alberta, Ontario and the Northwest Territories, some schools have been tested — which means the answer for your particular school is genuinely unknown until you ask.
Two of those programmes are worth knowing about in detail, because they set the standard you can reasonably point at:
- Nova Scotia tested every public school at least once, remediated every school found above the Health Canada guideline, and conducted follow-up tests afterwards to confirm the levels had come down. It also wrote radon requirements into its Design Requirements Manual for new provincial building projects.
- Prince Edward Island's Public Schools Branch began a three-year programme in autumn 2022 in collaboration with Health Canada, testing every school in the province following Health Canada's public buildings guide — detectors placed throughout each school, at least three months, during the heating season. It publishes the results.
Only Prince Edward Island and Yukon make all school testing results openly available to the public. Everywhere else, including provinces that have tested everything, you have to ask for them.
What this means for your question
If you are in Nova Scotia, PEI, New Brunswick, Saskatchewan, Quebec or Yukon, the result almost certainly exists. Your question is not “will you test?” but “what did the test say, and when was it?” That is a much easier request to make and a much harder one to deflect.
If you are in British Columbia, Alberta, Ontario, Manitoba, Newfoundland and Labrador or the Northwest Territories, your school may or may not have been included in whatever partial testing has happened. Ask.
And it is worth knowing what a partial programme can look like from the inside. The Calgary Board of Education tested 10 of its schools as a “representative sample” — around four per cent — found them all below the guideline, and concluded that no further testing was needed. That is a real decision a real board made, and it is exactly the kind of answer worth asking a follow-up question about: a sample tells you about the sample.
Who to ask
Start with the principal, who will usually redirect you, and copy or follow up with the board's facilities or operations department — they hold building records and make testing decisions. Individual schools rarely control this.
Other routes that work, depending on how your board is organised: the school council or parent advisory council, which can ask on behalf of many families rather than one; the joint health and safety committee, via a teacher or staff member, since they have standing to raise a workplace hazard formally; and trustees, if a board-wide answer is what you are after.
A question from a parent council carries more weight than an individual email and is harder to answer with a holding response.
What to ask for
Keep it short and specific. You are asking whether a number exists.
Dear [name],
I am a parent at [school]. I would like to ask whether the school building has been tested for radon.
If it has: when was it tested, what were the results, and are the records available?
If it has not: is there a plan to test during the coming heating season? I understand testing needs to run for at least three months between roughly October and April, so I appreciate the timing matters.
I am asking because Health Canada identifies radon as the second leading cause of lung cancer in Canada and its guideline applies to all indoor spaces including schools. I understand there is no legal requirement to test, and I am not suggesting anything is wrong — I would simply like to know whether the measurement has been done.
Thank you,
[you]
Two things that email does deliberately. It acknowledges there is no requirement, which removes the easiest way to deflect the question. And it says explicitly that you are not alleging a problem, which keeps the exchange cooperative — you will get a better answer from someone who does not feel accused.
How to read the answer you get
| If you are told… | What to ask next |
|---|---|
| “The school was tested and results were below the guideline.” | Ask when, how many detectors, which rooms, and whether the report is available. A good answer will withstand this easily. |
| “We did a test.” | How many detectors? Health Canada's protocol requires one in each occupied room in contact with the ground, one per 200 m² in larger spaces such as a gym or library, plus quality-control detectors. One reading for a whole school is not a compliant measurement. |
| “We tested in the spring / with a monitor.” | Long-term measurement of at least three months during the heating season is the method for deciding whether to act. Short-term readings are not. |
| “It was tested some years ago.” | Ask whether there have been renovations, ventilation work, an energy retrofit or a change in how ground-floor rooms are used. Any of those is a reason to retest. |
| “There is no requirement to test.” | Accurate. The follow-up is simply whether they would consider it anyway, and what it would take. |
| “We will look into it.” | Ask for a date. Without one, the seasonal window tends to close on its own. |
What the numbers mean
If you are given results, here is how Health Canada frames them.
| Result | Health Canada guidance |
|---|---|
| Below 200 Bq/m³ | No action recommended. Retest after renovations, ventilation changes or an energy retrofit. |
| 200–600 Bq/m³ | Remedial action within two years |
| Above 600 Bq/m³ | Remedial action within one year |
No level is risk-free, and risk accumulates with concentration multiplied by time. But context matters: these are timelines measured in years, not emergencies. A result above the guideline means the building should be fixed on a schedule, not evacuated. Mitigation in a school is the same technique used in houses, at a larger scale — and it typically reduces levels by more than 80%.
If the result is above the guideline
What you want to see is a plan with dates, not a promise.
- Which rooms were above, and what interim steps are being taken in those rooms.
- Who is doing the mitigation — a certified professional, ideally one listed under the Canadian National Radon Proficiency Program.
- When, against Health Canada's timelines.
- How it will be verified afterwards. Health Canada recommends that the follow-up test not be carried out by the company that installed the system.
- How results will be communicated to families.
Ask for those five things in writing. A board that is handling it properly will have most of the answers already.
What about the daycare?
Largely the same, with two differences. Younger children spend more of their day in the building and are often in rooms at or below grade. And licensed childcare is regulated separately from schools, which is why the one Canadian requirement that does exist — Interior Health's, in British Columbia — applies to childcare rather than to schools.
Ask the operator directly. Small operators frequently have not considered it and are often receptive, particularly since a single-room facility needs very few detectors.
More detail: radon in workplaces, schools and daycares.
And your own home
Worth saying plainly: a child spends far more hours at home than at school. If the school question has prompted you to think about radon, testing your own house is the higher-value action and it is entirely within your control.
See where to place a radon test kit and radon in Canadian basements. A long-term home test kit is inexpensive, needs no installation, and includes laboratory analysis.
Common questions
Are schools in Canada required to test for radon?
No province or territory requires it, and there is no general federal requirement. Several have done it anyway: Health Canada records that all public schools have been tested in Nova Scotia, Prince Edward Island, New Brunswick, Saskatchewan, Quebec and Yukon. Schools operated by a First Nations band council are federally regulated as workplaces. In British Columbia, Interior Health ordered testing in licensed childcare facilities within its region.
Has my province tested its schools?
All public schools have been tested in Nova Scotia, PEI, New Brunswick, Saskatchewan, Quebec and Yukon. Some have been tested in British Columbia, Alberta, Ontario and the Northwest Territories. Only PEI and Yukon publish all results openly.
Should I be worried?
Most buildings test below the guideline. Radon is a long-term, cumulative risk rather than an immediate one, and Health Canada's response timelines are measured in years. Asking is sensible; alarm is not warranted by the question itself.
Can I test the school myself?
No — you would need the board's permission to place detectors in a building you do not control, and a test done without their involvement will not be accepted as a basis for action. Ask them to test.
How many detectors should a school use?
One in each occupied room in contact with the ground, one per 200 m² in larger spaces, plus quality-control detectors. For a typical elementary school that is dozens, not one.
How long does it take?
At least three months of measurement, ideally during the heating season, plus laboratory turnaround. Detectors placed in the autumn produce results in the spring.
Who pays?
The school board or the facility operator. Testing is inexpensive relative to most building expenditure — the cost driver is the number of occupied ground-contact rooms.
If your school wants to test
Boards and operators sometimes ask a parent what testing would actually involve, which is an awkward question to answer from a standing start.
Anyone at the school or board can email support@radontest.ca and we will tell them how many detectors the building needs and what it would cost, without obligation. We supply long-term detectors listed under the Canadian National Radon Proficiency Program, analysed by a C-NRPP-certified, ISO 17025-accredited laboratory — the combination Health Canada advises people to look for — and we handle logistics and the record. We are listed by Take Action on Radon and are members of CARST.
We do not perform mitigation, so we have no financial interest in what the results say. If a parent council simply wants the detector arithmetic so it can put a real number in front of a board, ask for that — it is a question we are happy to answer, not a sales enquiry.
Read next
Radon in workplaces, schools and daycares · Where to place a radon test kit · What to do if a result is above 200 · The Canada radon map
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 (canada.ca/radon). This page describes publicly available guidance and is not legal or health advice. Free to reproduce and distribute with attribution.
Sources
Health Canada, Guide for Radon Measurements in Public Buildings; Health Canada, Canadian radon guideline; Health Canada, Radon — Reduction Guide for Canadians; Health Canada, Radon action guide for provinces and territories; CAREX Canada, Radon in schools: a summary of testing efforts across Canada; Community Care and Assisted Living Act, S.B.C. 2002, c. 75; Radon Awareness and Testing Act, SA 2017, c. R-2.5 (never proclaimed); International Agency for Research on Cancer, Monograph Vol. 100D; C-NRPP.