In Canada, radon obligations for employers come from two places that are frequently confused: a binding exposure limit that applies to federally regulated workplaces, and general duty provisions that apply to everyone else. This brief sets out both, statute by statute, with the operative wording.
Summary of duties: Federally regulated employers must ensure no employee is exposed to an annual average above 200 Bq/m³ from January 30, 2027 (COHSR s. 10.26(4), as amended by SOR/2026-10). Provincially regulated employers have no radon-specific numeric limit but owe a general duty to take reasonable precautions against recognized hazards. Health Canada's 200 Bq/m³ guideline is the benchmark in both cases. Hazardous-substance records must be retained 30 years federally.
1. Federal — Canada Labour Code, Part II
1.1 The exposure limit
Subsection 10.26(4) of the Canada Occupational Health and Safety Regulations, as amended by SOR/2026-10, reads:
"The employer must ensure that no employee, other than a nuclear energy worker as defined in section 2 of the Nuclear Safety and Control Act, is exposed in any year to a concentration of radon that on average, over the year, is higher than 200 Bq/m³."
Key features. The duty is on the employer ("must ensure"), not framed as a prohibition on exposure. The metric is an annual average. Nuclear energy workers are excluded, falling under the Canadian Nuclear Safety Commission's regime. The previous limit was 800 Bq/m³.
Instrument: SOR/2026-10, made by the Governor in Council (P.C. 2026-49) and registered January 30, 2026; published Canada Gazette Part II, Vol. 160, No. 3, February 11, 2026.
Coming into force: section 77(1) provides that the Regulations "come into force on the first anniversary of the day on which they are registered" — January 30, 2027.
1.2 The limit prescribes no method
SOR/2026-10 sets a concentration limit. It does not specify test duration, protocol, device type, laboratory accreditation, or how compliance is to be demonstrated. That gap is filled by Health Canada's Guide for Radon Measurements in Public Buildings, which is guidance rather than law but is the recognized method: long-term measurement of at least three months during the heating season, a detector in every occupied ground-contact room, one per 200 m² in larger rooms, C-NRPP-approved devices analyzed by a certified laboratory, with quality-control duplicates and blanks.
The practical consequence for an employer is that the method is a choice, and the defensible choice is the recognized one, documented.
1.3 Investigation and the qualified person
Section 10.4(1) provides that where "the health or safety of an employee is likely to be endangered by exposure to a hazardous substance in a work place, the employer shall, without delay" — and paragraph (1)(a) — "appoint a qualified person to carry out an investigation in that regard."
Two features. The obligation is triggered by likelihood of endangerment, not by a confirmed exceedance, and it operates "without delay." And "qualified person" is defined by reference to knowledge, training and experience: it is a competence test, not a certification requirement. No provision requires C-NRPP certification. Health Canada's public-buildings guide states that a C-NRPP Measurement Professional would ideally be involved in the measurement strategy — a recommendation, not a legal condition.
The circumstances that trigger an investigation include, under s. 10.4(2), where the level of ionizing radiation is likely to exceed the levels referred to in s. 10.26 — which is where the radon limit sits.
1.3.1 A note on "qualified person" versus "certified professional"
Section 10.4 is sometimes cited in support of the proposition that radon testing must be performed by a C-NRPP certified professional. The section does not say so. It requires the appointment of a qualified person, a term defined by knowledge, training and experience. C-NRPP certification is strong evidence of that competence and is the prudent choice where a building is complex, where results are likely to be contested, or where a third-party opinion is needed. It is not a condition imposed by the regulation, and the distinction matters when an employer is deciding what it is legally required to do as against what a service provider recommends. Detailed treatment: the qualified person question.
1.4 Records — and what a record must contain
Section 10.3(1), as replaced, requires that "every employer must keep a record of each hazardous substance that is used, produced or handled in the work place by the employer, employees or contractors or that is stored in the work place by the employer, employees or contractors for use in the work place." Note the inclusion of contractors — the register is not limited to substances the employer itself introduces.
Where air sampling is carried out, the regulations set out the content of a test record at s. 10.19(5):
- the date, time and location of the test;
- the hazardous substance in respect of which the test was made;
- the sampling and testing method used;
- the result obtained; and
- the name and occupation of the person who made the test.
Section 10.19 governs airborne chemical agents, while radon is dealt with under s. 10.26 as ionizing radiation — but this is the content standard the regulations set for air sampling test records and the template the industry works to for radon. A laboratory report alone does not meet it: the lab reports a result, while the date, location, method and identity of the person who performed the test are field information the employer must capture and retain. The fuller document set is set out in what a compliant radon record contains.
Retention: the amendments harmonize record retention across the five OHS regulations at 30 years for hazard investigation and air sampling records.
1.5 Enforcement
Administered by the Labour Program of Employment and Social Development Canada. The enforcement tools available under Part II of the Code include directions to terminate a contravention, directions in respect of a danger (which can require an activity to cease), and prosecution for offences under the Code. The SOR/2026-10 package made consequential amendments to the Administrative Monetary Penalties (Canada Labour Code) Regulations, so contraventions of the amended provisions may also attract AMPs. A worker may complain directly to the Labour Program without first raising the matter with the employer.
1.5.1 Disclosure routes
Two points employers sometimes overlook. First, enforcement activity is not necessarily private: regulators may publish enforcement actions, and a worker complaint creates a record. Second, for departments and agencies within the federal public administration, radon measurement results and related correspondence are records subject to the Access to Information Act. An employer in that category should assume its radon file may be requested, and should be comfortable with how it reads.
1.5.2 Civil liability
Separately from regulatory enforcement, radon exposure raises the ordinary question of civil liability to workers. Lung cancer attributable to radon typically presents decades after exposure, which is the practical reason the 30-year record retention period exists: the record created today is the evidence available to whoever has to answer the question later — whether that is the employer defending its conduct or a worker establishing exposure. This is a matter for legal advice rather than for us, but it is the strongest argument for building the record properly the first time.
1.6 Parallel instrument
The same 200 Bq/m³ limit was added to the Oil and Gas Occupational Safety and Health Regulations. The radon provision was removed from the On Board Trains Occupational Health and Safety Regulations, radon exposure not being an issue in that setting.
2. Who is federally regulated
Jurisdiction under the Canada Labour Code follows the nature of the undertaking, not its location: air, rail, interprovincial road and marine transportation; pipelines; chartered banks; telecommunications and broadcasting; postal and courier services; grain elevators, feed and seed mills; uranium mining and processing; Crown corporations; First Nations band councils; Parliament and the federal public administration. Approximately 1.3 million employees, about 8% of the Canadian workforce. Detail and edge cases: which rules apply to your workplace.
3. Provincial and territorial — the general duty
No province or territory has enacted a radon-specific workplace exposure limit equivalent to the federal one. What applies instead:
General duty clauses. Every provincial and territorial occupational health and safety statute requires employers to take every precaution reasonable in the circumstances for the protection of workers. These attach to recognized hazards without enumerating them. Radon is classified by the International Agency for Research on Cancer as a Group 1 carcinogen.
Ontario. The province publishes workplace radon guidance built on the NORM framework: an area is "unrestricted" at 200 Bq/m³ or less; 200–800 Bq/m³ is "NORM Management"; and where the annual average is expected to exceed 200 Bq/m³, measurements should be made to estimate it. Ontario also states that an occupationally exposed worker should not be exposed to an annual average exceeding 3,000 Bq/m³, corresponding to an effective dose of 20 mSv. Radon is not a designated substance under O. Reg. 490/09. Separately, R.R.O. 1990, Reg. 854 (Mines and Mining Plants) governs radon and radon progeny in mining.
British Columbia. The Occupational Health and Safety Regulation contains general duty provisions on avoiding occupational disease and detailed ionizing radiation provisions at ss. 7.17–7.25. Separately, Interior Health ordered childcare facilities in its region to test for radon in 2017, relying on the medical health officer's power under the Community Care and Assisted Living Act to attach terms to a licence.
New Brunswick. WorkSafeNB publishes workplace radon guidance for employers.
Alberta. General duty under the OHS Act, with a published OHS bulletin on radon in the workplace. The Radon Awareness and Testing Act (SA 2017, c R-2.5) received royal assent in December 2017 but was never proclaimed into force and lapsed in 2023 — Alberta has no radon-specific testing requirement, notwithstanding sources that still describe it as law.
Quebec. Neither the Act respecting occupational health and safety nor the Regulation respecting occupational health and safety (RSST) sets a numeric radon limit. Employers carry prevention-programme obligations under the CNESST regime extending to identified workplace risks.
NORM guidelines. The Canadian Guidelines for the Management of Naturally Occurring Radioactive Materials classify workplace radon: below 200 Bq/m³ unrestricted; 200–800 NORM Management; 800–3,000 Radiation Protection Management.
Jurisdiction-by-jurisdiction detail: workplace radon rules by province.
4. Related duties by building type
Schools and childcare. Provincially regulated in almost all cases; band-operated schools and childcare are federal. Yukon announced in 2017 a phased-in licensing requirement for child care centres and family day homes; BC's Interior Health region ordered testing in 2017. No other Canadian jurisdiction requires it. See schools and daycares.
Multi-unit residential. Health Canada's public-buildings guide covers multi-unit residential dwellings, with its own protocol. Landlord and property-manager duties arise under provincial residential tenancy, public health and OHS law rather than a radon-specific instrument. See landlords and property managers.
New construction. The 2025 National Building Code requires at least a passive vertical radon stack in new dwelling units and home-type care occupancies. As a model code it has force only where adopted; BC, Alberta, Ontario and Quebec maintain their own codes. See rough-in requirements for builders.
4.1 Verification after mitigation
Health Canada's guidance is that a short-term test be completed a minimum of 24 hours after mitigation work is finished, in the same locations originally tested, with a long-term test during the next heating season to confirm the reduction holds, and retesting every five years thereafter. 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.
Nothing in the regulations addresses who performs that verification. Health Canada's guidance does: its Radon — Reduction Guide for Canadians states that "to avoid conflict of interest, the test should not be performed by the company that installed the radon mitigation system." That recommendation appears in Health Canada's residential guidance; the Guide for Radon Measurements in Public Buildings does not set out a post-mitigation verification protocol, so there is no workplace-specific Canadian standard on the point. It is a recommendation rather than a legal requirement, but it is the position of the federal health authority, and employers procuring measurement, mitigation and verification as a single package should consider whether the verification step ought to be separately sourced. See post-mitigation radon verification.
5. Practical implications
- A federally regulated workplace legally compliant today at 500 Bq/m³ is non-compliant on January 30, 2027 with nothing about the building having changed.
- An annual-average duty cannot be discharged without measurement, and the recognized measurement takes at least three months of heating season.
- The wording shift from "no employee shall be exposed" to "the employer must ensure" moves the question from outcome to demonstrable diligence.
- A 30-year retention period implies the record, not the reading, is the durable asset.
- For provincially regulated employers, the operative risk is inaction after the hazard has been identified — typically by a worker or committee raising it.
Frequently asked
Is workplace radon testing legally required in Canada?
No statute uses those words. Federally regulated employers must ensure an annual average below 200 Bq/m³ from January 30, 2027, which cannot be demonstrated without measurement. Provincially regulated employers owe a general duty regarding recognized hazards, of which radon is one.
Does the federal limit apply to provincial workplaces?
No. It applies to workplaces under Part II of the Canada Labour Code only.
Is a C-NRPP certified professional legally required?
No provision requires it. The COHSR requires a "qualified person," defined by knowledge, training and experience. Health Canada's guide states that a C-NRPP Measurement Professional would ideally be involved in the measurement strategy.
How long must radon records be kept?
Thirty years, under the amended provisions on hazard investigation and air sampling records.
What is the enforcement mechanism?
Labour Program inspection and audit, compliance orders, and administrative monetary penalties. Worker complaints may be made directly to the Labour Program.
Read next
What a compliant record contains · The qualified person question · Phased compliance · Rules by province
Sources
Canada Labour Code, Part II; Canada Occupational Health and Safety Regulations (SOR/86-304), Part X and s. 10.26(4) as amended; Canada Gazette, Part II, Vol. 160, No. 3 (SOR/2026-10) and the accompanying Regulatory Impact Analysis Statement; Oil and Gas Occupational Safety and Health Regulations (SOR/87-612); 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) and Canadian radon guideline; Canadian Guidelines for the Management of Naturally Occurring Radioactive Materials; Government of Ontario, Radon in the workplace; R.R.O. 1990, Reg. 854; 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); CCOHS, Radon in Buildings; C-NRPP.
Last reviewed against the Canada Gazette text and the sources listed. 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 brief describes publicly available regulatory information and is not legal advice; obtain advice on your specific circumstances.