Asbestos is a long recognized, serious health hazard and a major cause of occupational illness. Asbestos-related diseases develop slowly and affected workers do not usually notice symptoms until the disease is at an advanced stage.

By law, employers, constructors and building owners have responsibilities to keep workers safe from exposure to asbestos. Supervisors and workers also have responsibilities as part of their general duties under the Occupational Health and Safety Act (OHSA).

Hazards of asbestos

Asbestos can be found in buildings built in Canada, especially if they were built prior to 1986.

According to O. Reg. 278/05 (Designated Substance –Asbestos on Construction Projects and in Buildings and Repair Operations), “building” means any structure, vault, chamber or tunnel including, without limitation, the electrical, plumbing, heating and air handling equipment (including rigid duct work) of the structure, vault, chamber or tunnel.

Breathing in asbestos fibres can lead to serious illnesses, such as:

  • lung cancer
  • asbestosis
  • mesothelioma
  • chronic pulmonary disease

Effects are latent and may not show up for 15 or more years.

Putting prescribed controls and protective measures in place can significantly reduce the risk of exposure. Asbestos can be found during different work activities, including:

  • demolitions
  • renovations
  • repairs

Asbestos-containing material

Asbestos-containing material (ACM) is defined in O. Reg. 278/05 as material that contains 0.5% or more asbestos by dry weight. ACM is most commonly found in, but not limited to:

  • fireproofing
  • transite sheeting/parging cement
  • residential insulation
  • drywall compound
  • pipe insulation

High-risk trades

Workers with the highest risk of exposure to ACM are:

  • insulators
  • plumbers
  • workers in demolition and renovation 
  • workers in power plants

Review our video Working with asbestos: What you need to know for additional helpful information on the hazards of asbestos.

Regulations protecting workers from exposure to asbestos

Under the Occupational Health and Safety Act (OHSA), asbestos is a “designated substance,” which means that exposure of a worker to asbestos is regulated to ensure measures and procedures are in place in the workplace to control, limit and restrict potential worker exposure.

There are two primary regulations related to worker exposure to asbestos:

  • O. Reg. 490/09 applies to employers in mining and in industrial workplaces carrying the risk of exposure to asbestos
  • O. Reg. 278/05  applies to, among other things, construction projects and certain building and repair operations

Workplace parties should review their obligations in the OHSA and the regulations carefully to determine which requirements apply to them.

Designated substances regulation

O. Reg. 490/09 identifies 11 substances as designated substances, including:

  • lead
  • mercury
  • arsenic
  • asbestos

Where it applies, the regulation provides maximum amounts of designated substances a worker can be exposed to in any given time period, and ways to control and assess those substances in the workplace. O. Reg. 490/09 does not apply at a construction project, to an employer who engages in construction.

Asbestos on construction projects and in building and repair operations regulation

O. Reg. 278/05 applies to the owner of a construction project (excluding owners of certain private residences), and every constructor, employer and worker engaged in or on the project. An employer includes a contractor or subcontractor who performs work or supplies services.

The regulation applies whether or not it is known or suspected that asbestos-containing materials (ACM) will be encountered during:

  • a construction project
  • the repair, alteration or maintenance of a building
  • the demolition of machinery, equipment, aircraft, ships, locomotives, railway cars and vehicles

This ensures that material that may be handled, disturbed or removed will be examined to determine whether it is ACM or will be treated as though it is ACM.

O. Reg. 278/05 requires that operations that may expose a worker to asbestos be classified (Type 1, Type 2, or Type 3) according to the asbestos hazard presented by the work, to protect those doing the work and, where applicable, others outside the work area.

The work classification can be thought of as being associated with a low, medium and high risk of exposure.

Based on the type of asbestos work, protective measures and procedures must be followed to control the exposure. The applicable control measures and procedures depend on the type of operation and may include requirements, such as those related to:

  • isolation enclosures
  • signage
  • training
  • personal protective equipment
  • decontamination facilities
  • work procedures

Learn more about the Regulation respecting asbestos on construction projects and in building and repair operations.

Asbestos in buildings

O. Reg. 278/05 applies to, among other things:

  • every project, its owner, and every constructor, employer and worker engaged in or on the project
  • the repair, alteration, or maintenance of a building, the owner of the building, and every employer or worker engaged in that work
  • work on a building that is necessarily incidental to the repair, alteration or maintenance of machinery or equipment in which ACM is likely to be handled, dealt with, disturbed or removed

It is important to note that the term "owner", as defined by the OHSA, includes tenants and occupiers of any lands or premises used or to be used as a workplace, among others. Depending upon the circumstances, a tenant may be considered an “owner” or may be considered an “occupier.” Once notified in writing by an owner of the location, related to the area they occupy, of ACM or material being treated as ACM, the occupier who receives that notice takes on the responsibilities set out in the regulation, including notifying and training their own workers.

Before beginning a project, section 30 of the OHSA requires the owner of a project to determine whether any designated substances are present at the project site and to prepare a list of all designated substances, including asbestos, that are present at the site. If any work on the project is tendered, the person issuing the tenders must include, as part of the tendering information, a copy of the list of all designated substances for the project, prepared by the owner.  The owner must ensure that a prospective constructor has received a copy of the list of designated substances before entering into a binding contract with the constructor.

Section 30 applies to project owners, including the owners of residential properties who undertake projects. It helps ensure that constructors, contractors and subcontractors, and workers who carry out these projects are aware of the presence of asbestos in these buildings, among other designated substances.

Buildings that contain material that may be or is being treated as ACM are covered by O. Reg. 278/05 even when no work is being done on them. The owners of these buildings are required to maintain an asbestos management program even when no work is being done on them.

Asbestos management programs in buildings

O. Reg. 278/05, section 8 requires ongoing asbestos management, often referred to as a plan, in various circumstances, such as when an owner:

  • knows or ought reasonably to know that ACM has been used in a building for any purpose related to the building, including insulation, fireproofing and ceiling tiles
  • chooses to treat material that has been used in the building for any purpose related to the building, including insulation, fireproofing and ceiling tiles, as though it is ACM

The asbestos management includes a number of requirements for owners, including:

  • asbestos record keeping
  • inspection of the material at reasonable intervals to determine its condition
  • notification of occupiers, employers, workers
  • worker training and instruction

Testing for asbestos in buildings

You can book a qualified consultant who will take samples and confirm if asbestos is present. The Occupational Hygiene Association of Ontario (OHAO) has a Directory of Consultants that can provide asbestos consulting services.

Health and safety information and services are offered by Ontario’s Health and Safety Associations and partners, such as the:

Tornado damaged buildings where asbestos may be present

While the scenario of a tornado damaging a building where asbestos may be present is not expressly addressed in the OHSA or the regulations, workplace parties may wish to familiarize themselves with the following laws that may apply.

Among other circumstances, O. Reg. 278/05: Asbestos on Construction Projects and in Buildings and Repair Operations, applies to:

  • every building where material that may be ACM has been used, and
  • the owner of the building

O. Reg. 278/05 also applies to every project, its owner, and every constructor, employer and worker engaged on the project.

The Occupational Health and Safety Act also has a general duty clause under clause 25(2)(h) which states that an employer must take every precaution reasonable in the circumstances for the protection of a worker.

This resource does not replace the Occupational Health and Safety Act (OHSA) and its regulations and should not be used as or considered legal advice. Health and safety inspectors apply and enforce these laws based on the facts they find in the workplace.

We have included links to other websites, but this does not mean that we endorse their information as compliant with the OHSA or the regulations.