The Occupational Health and Safety Act (OHSA) contains definitions in addition to the content under the following headings:

  • Part I Application
  • Part II Administration
  • Part II.1 Prevention Council, Chief Prevention Officer and Designated Entities
  • Part III Duties of Employers and Other Persons
  • Part III.0.1 Violence and Harassment
  • Part III.1 Codes of Practice
  • Part IV Toxic Substances
  • Part V Right to Refuse or to Stop Work Where Health or Safety in Danger
  • Part VI Reprisals by Employer Prohibited
  • Part VII Notices
  • Part VIII Enforcement
  • Part IX Offences and Penalties
  • Part X Regulations

Terms Used

These are some of the terms more commonly used in the Act.


Any place in, on or near to where a worker works. A workplace could be a building, a mine, a construction site, an open field, a road, a forest, a vehicle or even a beach. In determining whether a place is a workplace, the Ministry of Labour, Immigration, Training and Skills Development (MLITSD ) will consider questions such as: Is the worker being directed to work there?


Worker means any of the following, but does not include an inmate of a correctional institution or like institution or facility who participates inside the institution or facility in a work project or rehabilitation program:

  1. A person who performs work or supplies services for monetary compensation.
  2. A secondary school student who performs work or supplies services for no monetary compensation under a work experience program authorized by the school board that operates the school in which the student is enrolled.
  3. A person who performs work or supplies services for no monetary compensation under a program approved by a college of applied arts and technology, university or other post-secondary institution.
  4. Such other persons as may be prescribed who perform work or supply services to an employer for no monetary compensation.

A person who employs or contracts for the services of one or more workers. The term includes a contractor or subcontractor who performs work or supplies services and a contractor or subcontractor who undertakes with an owner, constructor, contractor, sub-contractor to perform work or supply services.


A person who undertakes a project for an owner and includes an owner who undertakes all or part of a project by himself or by more than one employer.

While the identification of a constructor is a fact-specific determination, the constructor is generally the person (such as the general contractor) who has overall control of a project. See also the publication entitled: Constructor Guideline: Health and Safety.


Prescribed means specified in regulations made under the Act.


A person, appointed by an employer, who has charge of a workplace or authority over a worker.


An owner includes a tenant, lessee, trustee, receiver, mortgagee in possession or occupier of the lands or premises. It also includes any person who acts as an agent for the owner.


A person who holds a logging licence under the Crown Forest Sustainability Act, 1994.

Regularly Employed

This term is not defined in the OHSA. However, by policy, MLITSD has interpreted the term to mean employed for a period that exceeds three months.

Workplace Harassment

Workplace harassment is defined in the OHSA as engaging in a course of vexatious comment or conduct against a worker in a workplace that is known or ought reasonably to be known to be unwelcome.

Workplace Violence

Workplace violence is defined in the OHSA as the exercise or attempted exercise of physical force by a person against a worker, in a workplace, that causes or could cause physical injury to the worker, or a statement or behaviour that it is reasonable for a worker to interpret as a threat to exercise physical force against the worker, in a workplace, that could cause physical injury to the worker.