Law and responsibilities

Asbestos work in Canada is controlled by provincial and territorial occupational health and safety law, by federal law for federally regulated workplaces, and by environmental rules on waste and the federal ban on new products. The rules differ in detail from one jurisdiction to another, but they share a structure: building owners must find and disclose asbestos, employers must classify the work and apply the precautions for each level, workers must be trained, and waste must be handled so that fibres do not escape. This lesson outlines the main laws, compares several provinces, and explains who is responsible for what.

Provincial and territorial OHS law

Every province and territory has an occupational health and safety act with a general duty for employers to protect workers and take every precaution reasonable in the circumstances. Asbestos is then covered by specific regulations, codes or guidelines that set exposure limits, require identification, classify work and prescribe precautions. Most Canadian jurisdictions now use an 8-hour exposure limit of 0.1 fibre per cubic centimetre (f/cc) for all forms of asbestos, the same value as the ACGIH threshold limit value, but check the limit and any excursion or ceiling limit that applies where you work.

Ontario in more detail

Because Ontario's regulation is detailed and widely referenced, it is a useful model. O. Reg. 278/05 defines asbestos-containing material as material containing 0.5 per cent or more asbestos by dry weight. Owners of buildings must keep a record of friable and non-friable asbestos-containing material, update it at least every 12 months, and tell occupiers about material in the parts they occupy. Before tendering or arranging demolition, alteration or repair work, the owner must prepare a report on asbestos-containing material that may be disturbed and give it to prospective constructors, who pass it to contractors and subcontractors. The regulation classifies work as Type 1, Type 2 or Type 3 operations, sets the precautions, respirators and training for each type, and requires written and oral notice to a Ministry inspector before a Type 3 operation or a Type 2 glove bag removal of one square metre or more of insulation. Lesson 6 explains the three types.

Elsewhere, the details differ. BC requires a qualified person to prepare an inventory of asbestos-containing materials before work that may disturb them, and employers must have a written exposure control plan. Since 1 January 2024, asbestos abatement contractors in BC must hold a licence and workers doing abatement must complete approved training and be certified. Alberta's OHS Code sets requirements for restricted areas, work practices and worker training, supported by the Alberta Asbestos Abatement Manual. Quebec requires building owners to locate friable flocking and heat insulation that may contain asbestos and to keep a register. Workers moving between provinces should never assume the rules are the same.

Who is responsible for what

Asbestos safety depends on several parties doing their part. A failure by one, such as an owner who does not disclose a known material, can expose workers who did everything else right.

Federal and environmental rules

The federal Prohibition of Asbestos and Products Containing Asbestos Regulations, in force since 30 December 2018, ban the import, sale, use, manufacture and export of asbestos and products containing it, with limited exclusions such as asbestos integrated into existing buildings and some military, nuclear and museum uses. They do not require removal of asbestos already in buildings, and they allow the management and removal of asbestos during renovation and demolition. Federally regulated workplaces, such as banks, airlines, rail, telecommunications and federal government buildings, follow the COHSR, which require an asbestos exposure management program where asbestos may be present. Waste rules are provincial and municipal, and transport of asbestos waste is covered by the federal Transportation of Dangerous Goods Regulations, discussed in Lesson 11.

Exposure limits are not safe levels

An exposure limit is a legal ceiling, not a line between safe and unsafe. Asbestos is a carcinogen with no known threshold, so the aim is always to keep exposure as low as reasonably achievable, not merely below the limit. Limits are also hard to measure at low levels, because standard phase contrast microscopy counts fibres down to about 0.01 f/cc only with large sample volumes. This is why asbestos regulations rely heavily on prescribed work methods by risk level or class, rather than on measured exposure alone.

# Comparing a measured exposure with an 8-hour limit and a 30-minute excursion limit
TWA_LIMIT = 0.1        # f/cc, 8-hour
EXCURSION_LIMIT = 1.0  # f/cc, 30-minute (OSHA; Canadian rules vary)

samples = [  # (duration in minutes, concentration in f/cc)
    (30, 0.9),   # dry scraping before controls were fixed
    (210, 0.06),
    (240, 0.02),
]
total_min = sum(d for d, _ in samples)
twa = sum(d * c for d, c in samples) / 480
print(f"time sampled: {total_min} min")
print(f"8-hour TWA: {twa:.3f} f/cc -> {'above' if twa > TWA_LIMIT else 'below'} the 0.1 limit")
peak = max(c for d, c in samples if d >= 30)
print(f"highest 30-minute result: {peak} f/cc -> {'above' if peak > EXCURSION_LIMIT else 'below'} the 1.0 excursion limit")

time sampled: 480 min
8-hour TWA: 0.092 f/cc -> below the 0.1 limit
highest 30-minute result: 0.9 f/cc -> below the 1.0 excursion limit

In this illustrative case, the shift average is under the 8-hour limit, but the 30-minute result during dry scraping was close to the excursion limit. The fix is not to celebrate the average but to correct the method that caused the peak, because asbestos risk depends on total dose and peaks contribute to it.

Enforcement and due diligence

Asbestos rules are actively enforced. Ministry and WorkSafe inspectors visit renovation and demolition sites, review asbestos reports and notices, and issue orders to stop work where asbestos is being disturbed without the required precautions. Convictions for asbestos offences have led to substantial fines for corporations and, in some cases, for directors and supervisors personally, and environmental regulators prosecute illegal dumping of asbestos waste. In BC, the 2024 licensing regime gives WorkSafeBC the power to suspend or cancel the licences of contractors who do not comply.

When something goes wrong, employers and supervisors may defend themselves by showing due diligence: that they took every precaution reasonable in the circumstances to prevent the harm. For asbestos, due diligence is shown by documents and actions, not good intentions. Useful evidence includes the asbestos report obtained before work, records of task classification, the written procedures and exposure control plan, training and certification records for every worker, inspection checklists, air monitoring and clearance results, waste receipts, and records of how discoveries and incidents were handled.

Due diligence also covers the choice of contractors. Owners and general contractors should check that asbestos subcontractors are qualified, licensed or certified where required, experienced with the type of work, and insured, and should review their written procedures before awarding the work. A low bid that leaves out enclosures, monitoring or proper disposal is a warning sign, not a saving: the cost of an uncontrolled release, including clean-up of a contaminated building, stopped work, orders and prosecution, is far higher than the cost of doing the work properly.

Finally, due diligence is continuous. Supervisors should check controls during the work, not only at the start, and should record what they find and what they correct. A record showing that a torn barrier was found and repaired within minutes is evidence of a working system, not of failure.