Joint health and safety committees in Ontario: when does your workplace need one

The thresholds, in plain terms

The Occupational Health and Safety Act sets two separate obligations based on how many workers an employer regularly employs at a workplace.

At 20 or more workers, a joint health and safety committee is required [clause 9(2)(a)]. At 6 to 19 workers, a health and safety representative is required instead [section 8]. Below 6 workers, neither obligation applies under these sections, though other health and safety duties still do.

The number that matters is how many workers are regularly employed at the specific workplace, not across all of an employer's locations. Each workplace is assessed on its own headcount.

Two workplaces that follow different rules

Construction projects follow a modified threshold: a committee is required on a project where 20 or more workers are regularly employed AND the project is expected to last three months or more [clauses 9(1)(a) and 9(2)(a)]. A short construction project does not trigger the obligation even if the worker count crosses 20.

Designated substance workplaces cut the other way: if a regulation under the OHSA designates a substance at a workplace — lead, asbestos, benzene and others are designated — a committee is required regardless of how many workers are employed [clause 9(2)(c)]. The 20-worker threshold simply does not apply.

How the committee must be structured

Committee size scales with headcount, and worker representation is a hard rule rather than a target.

Certified members — the training requirement inside the committee

Having a committee is not the whole obligation. Under the OHSA, at least one worker member and at least one employer member of every JHSC must be certified.

Certification requires completing an approved two-part training program — Part 1 and Part 2 — from a Chief Prevention Officer-approved provider, and being certified by the Chief Prevention Officer. The Ministry of Labour, Immigration, Training and Skills Development maintains the list of approved providers; there are over 270 across Ontario offering classroom, distance, and eLearning formats.

Certification is valid for three years from the successful completion of Part 2. To stay certified, the member must complete an approved refresher program within that three-year window. The employer must keep proof of workers' JHSC certification and make it available to a Ministry inspector on request.

A newly formed committee will typically have uncertified members at the start — that is expected. The employer's duty is to ensure the required members are enrolled in approved training. Until certification is in place, the committee can operate but the employer is not yet fully compliant with the certified-member requirement.

The health and safety representative — for workplaces with 6 to 19 workers

A workplace with 6 to 19 workers that does not require a JHSC must instead have a health and safety representative [section 8 of the OHSA]. The representative is selected by the workers themselves — or by the trade union where one has bargaining rights — and must not exercise managerial functions.

The HSR role is not a smaller version of a committee. It is a distinct mechanism with its own duties: identifying workplace hazards, making recommendations to the employer, inspecting the workplace regularly, and being consulted on health and safety matters. Employers must respond in writing to HSR recommendations.

Basic training for HSRs — a one-day eLearning program — is available through Ministry-approved providers.