Hazard assessment: how to do one (and why it's the law)

Hazard assessment is the single most important activity in Canadian workplace safety, because it is where you find the things that can hurt someone before they do. It is also, in much of the country, a legal duty in its own right — Alberta's OHS Code requires hazard assessments to be done and documented in writing, and every Canadian jurisdiction expects hazards to be identified and controlled before work begins. This guide covers how to do a hazard assessment properly.

The two levels of assessment

Most Canadian safety systems use two layers. The first is the formal hazard assessment — a documented, considered look at a job or the workplace, done in advance and reviewed periodically and after changes. The second is the field-level hazard assessment (FLHA), a short assessment the crew completes at the worksite at the start of a shift or task, catching the conditions that only exist on the day — weather, ground conditions, other trades working nearby. Good programs use both: the formal assessment sets the safe method, and the FLHA confirms it still fits today's reality.

How to do a hazard assessment

The method is consistent across provinces. First, pick the job or area to assess, prioritizing higher-risk and non-routine work. Second, break the job into a logical sequence of basic steps — enough that no significant hazard hides between them, but not so granular it becomes unusable. Third, for each step, identify the hazard by asking what can go wrong: run through the common categories — struck-by, caught-in or between, falls, electrical, chemical exposure and WHMIS products, ergonomic and manual handling, thermal, noise, and environmental hazards like traffic or the public. Fourth, assess the risk (how likely, how severe) and decide on controls. Finally, involve the workers who do the job — they know where the risk really is — and record it.

The hierarchy of controls

For each hazard, choose the control using the hierarchy of controls, in order of effectiveness. Eliminate the hazard if you can — the most effective control, because a hazard that is not there cannot hurt anyone. Failing that, substitute something less hazardous. Then use engineering controls — guards, ventilation, barriers — that reduce exposure without relying on the worker. Then administrative controls and safe work procedures — training, rotation, permits, signage. Personal protective equipment comes last, because it protects only the individual wearing it and only when worn correctly. An assessment whose every control is "wear PPE and be careful" has skipped the more reliable options.

Keeping it real

A hazard assessment earns its keep at the point of work, not in a filing cabinet. Review it with the crew before the task, get the people doing the job to sign that they understand it, and treat it as a living record — update it after any incident, near miss or change. Kept together and current, your hazard assessments are also some of the strongest evidence you can show a WorkSafe/WCB officer or a COR auditor that you plan work safely rather than react to incidents. Always check your provincial regulator's requirements for the documentation and review your province expects.