Ontario OHSA: the health and safety rules every employer must meet

Ontario has the largest workforce in Canada and one of the most developed occupational health and safety regimes to match it. The Occupational Health and Safety Act — the OHSA — is the backbone, supported by sector regulations including the Construction Projects regulation (O. Reg. 213/91). If you employ people in Ontario, these are the rules an inspector from the Ministry of Labour, Immigration, Training and Skills Development will hold you to. This guide walks through the ones that matter most.

The internal responsibility system

The OHSA is built on the "internal responsibility system" — the idea that everyone in the workplace, from the CEO to the newest worker, shares responsibility for health and safety and that the people closest to a hazard are best placed to deal with it. In practice that means the Act assigns specific duties to employers, supervisors and workers, and expects them to work together rather than wait for a government inspector. Understanding this principle explains why so many of the specific requirements exist: they are the machinery that makes shared responsibility real.

The three rights of every worker

The OHSA gives every worker three fundamental rights: the right to know about hazards in their work, the right to participate in keeping the workplace safe (through the committee or representative, and by raising concerns), and the right to refuse work they believe is dangerous. Employers cannot penalize a worker for exercising these rights, and the Act sets out a specific procedure for a work refusal.

Written policy and program

An employer that regularly employs more than five workers must have a written occupational health and safety policy, reviewed at least once a year, and must develop and maintain a program to implement it. This is the document a prospective client, a constructor prequalifying a sub, or an inspector will ask to see first. It should name responsibilities by role, describe how hazards are identified and controlled, and connect to your actual training and inspection records.

Committees and representatives

Worker participation is scaled to the size of the workplace. Where 20 or more workers are regularly employed, a joint health and safety committee (JHSC) is required, with at least one worker member and one management member holding JHSC certification. Where six to 19 workers are regularly employed, a health and safety representative must be selected by the workers. Construction projects have their own thresholds. The committee inspects the workplace, reviews incidents and makes recommendations — it is the beating heart of the internal responsibility system.

Working at Heights training

Ontario is strict about falls, the leading cause of construction fatalities. Any worker on a construction project who uses a fall-protection method must complete a Working at Heights (WAH) training program delivered by a provider approved by the Chief Prevention Officer (CPO). The certificate is valid for three years, after which a refresher is required to stay compliant. Letting a WAH certificate lapse is one of the most common — and most avoidable — ways an Ontario contractor falls offside, because the worker simply cannot legally be on the tools until it is renewed.

WHMIS, orientation and supervision

Employers must run a WHMIS program for hazardous products — labels, safety data sheets and worker training — and must provide information, instruction and supervision to protect workers, with particular attention to new and young workers. Competent supervision is a legal requirement, not a nicety: a supervisor must know the Act and the hazards of the work.

Where Complys fits

Ontario's requirements are not complicated so much as relentless: a policy that must be reviewed yearly, WAH certificates that expire on a three-year clock, JHSC members whose certification must stay current, WHMIS training for every worker. Complys holds all of it in one place, writes your policy and program, and warns you before any certificate or review date passes — so the OHSA becomes a score you can watch rather than a stack of dates you have to remember. See our guide to working at heights across Canada and the joint health and safety committee guide, and remember that OHS is provincial — Ontario's rules are not the same as BC's or Alberta's.