The Standard Definition (CSA Z1003 / National Standard of Canada)

Under the National Standard of Canada and ISO 45003, Reasonable Care is validated through a "balancing test." To meet the standard of being "reasonably practicable," an employer must weigh:

Severity of Harm: How badly could this impact the employee's mental health?
Likelihood: How often is this stressor occurring?
State of Knowledge: What should the employer reasonably know about this hazard (e.g., industry best practices)?
Availability of Controls: Are there known ways to fix the issue?
Proportionality: Is the cost/effort of the fix grossly disproportionate to the risk?

What is Reasonable Care? Definition and Workplace Impact

Reasonable Care is the degree of caution and concern for the safety of others that an ordinarily prudent and rational person would use in the same circumstances. In PHS, this means that if a hazard (like workplace bullying or extreme chronic overwork) has foreseeability, the employer must take action to address it (i.e. Duty of Care).

If an incident occurs, the courts or health and safety inspectors won't ask, "Did you stop this from happening?" They will ask, "Did you take every precaution reasonable in the circumstances to prevent it?

Why Reasonable Care Matters for Leaders & HR

All of these efforts must be captured through documentation. When a risk is identified, recording the specific steps taken to mitigate it provides the necessary evidence that, while the harm may have been foreseeable, the organization exercised Reasonable Careto prevent it.

The power of this data lies in its application. Per the National Standard recommendations, these insights should not exist in a vacuum but must be directly incorporated into your PHS Integrated Management System (IMS).

Demonstrating Reasonable Care is the primary way to establish a due diligence defense. Operating through a PHS informed-lens gives HR a framework to request budget for PHS initiatives—if a risk is identified, taking "Reasonable Care" usually requires an investment in training or resources.

Expert Insight

This is where the shift from OHS to PHS is most tangible. In physical safety, reasonable care might mean providing a harness; in PHS, it means providing clear role expectations and manageable workloads.

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