Print This Page

Supervisory Engagement in Construction

Safe At Work Ontario

Disclaimer: This resource has been prepared to help the workplace parties understand some of their obligations under the Occupational Health and Safety Act (OHSA) and regulations. It is not legal advice. It is not intended to replace the OHSA or the regulations. For further information please see full disclaimer.

Supervisors are the employer's representative on a construction project. Their responsibilities include monitoring the project's progress and ensuring workers' health and safety. Supervisors plan the project's work and oversee its implementation. They assign tasks to their workers and provide them with advice and direction. Supervisors are the main vehicle of communication for their employer and for the other employers on the project.

General duties of workplace parties under the OHSA

Constructors, employers and supervisors must comply with the provisions of the Occupational Health and Safety Act (OHSA) and its regulations.


Constructors' responsibilities include:

  • ensuring the required measures and procedures are carried out on the project [OHSA Section 23(1)(a)]
  • ensuring every employer and every worker performing work on the project complies with the OHSA and its regulations [OHSA Section 23(1)(b)]
  • ensuring the health and safety of workers on the project is protected [OHSA Section 23(1)(c)]
  • giving to a Ministry of Labour (MOL) director notice in writing of a project, containing information required under in the Construction Regulation, before commencing work on the project, [OHSA Section 23(2)]
  • ensuring each prospective contractor and subcontractor has received a copy of any designated substances' list before entering into a binding contract for the supply of work on the project [OHSA Section 30(4)]
  • appointing a supervisor for every project at which five or more workers will work at the same time [Construction Regulation Section 14(1)]


Employers' responsibilities include:

  • instructing, informing and supervising workers to protect their health and safety [OHSA Section 25(2)(a)]
  • appointing competent persons as supervisors [OHSA Section 25(2)(c)]
  • taking every precaution reasonable in the circumstances for a worker's protection [OHSA Section 25(2)(h)]
  • preparing and reviewing, at least annually, a written occupational health and safety policy, and developing and maintaining a program to implement that policy if the workplace has six or more regularly employed workers [OHSA Section 25(2)(j)]
  • posting a copy of the occupational health and safety policy in the workplace in a spot where workers will most likely see it [OHSA Section 25(2)(k)]
  • taking every precaution reasonable in the circumstances for a worker's protection [OHSA Section 25(2)(h)]
  • appointing a supervisor if the employer has five or more workers on the project [Construction Regulation Section 15(1)]


Supervisors' responsibilities include:

  • ensuring workers work in compliance with required protective devices, measures and procedures [OHSA Section 27(1)(a)]
  • ensuring workers use or wear any equipment, protective device or clothing required by the employer [OHSA Section 27(1)(b)]
  • advising workers of any potential or actual health or safety danger known by the supervisor [OHSA Section 27(2)(a)]
  • providing workers, when required, with written instructions on any measures and procedures to be taken for the workers' protection [OHSA Section 27(2)(b)]
  • taking every precaution reasonable in the circumstances for a worker's protection [OHSA Section (2)(c)]
  • supervising the work on the project at all times, either personally or by having an assistant who is a competent person do so when the supervisor is unavailable [Construction Regulation Sections 14(2) and 15(2)]
  • inspecting or having the supervisor's assistant inspect, at least once a week, all machinery and equipment, including fire extinguishing equipment, magazines (storage for flammables and explosives), electrical installations, communications systems, sanitation and medical facilities, buildings and other structures, temporary supports and means of access and egress at the project to ensure workers are not endangered [Construction Regulation Sections 14(3) and 14(4)]

More information about construction project safety

Toll–free Number

Call 1–877–202–0008 any time to report critical injuries, fatalities or work refusals. Call 8:30 a.m. to 5 p.m. Monday to Friday for general inquiries about workplace health and safety. Always call 911 in an emergency.