I get this question a lot from Ontario employers who've read about CSA Z1003 and assume it means they're legally required to run a full psychological health and safety program. It's a reasonable assumption to make. It's also wrong.
Let's be precise about what Ontario law actually requires, because the gap between "legally mandated" and "strongly recommended" matters when you're deciding where to put your compliance effort.
The Short Answer
No. There is no section of the Occupational Health and Safety Act (OHSA) that requires a standalone "psychological health and safety program" by that name. What OHSA requires is narrower: a written workplace violence program and a written workplace harassment program, plus a general duty of care that applies to every hazard in your workplace, psychological or otherwise.
CSA Z1003, the national standard most people mean when they say "psychological health and safety program," is voluntary. It's good practice. It is not law in Ontario.
What OHSA Actually Requires
This is where I want to get specific, because vague answers are how employers end up either overbuilding a program they don't legally need or underbuilding one they do.
Under Part III.0.1 of OHSA:
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Section 32.0.1 requires every employer to prepare written policies on workplace violence and workplace harassment, and to review those policies at least once a year. If you regularly employ six or more workers, the policies have to be posted somewhere workers will see them.
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Section 32.0.2 requires employers to develop and maintain an actual workplace violence program, not just a policy statement. That program has to include measures to control the risks identified, procedures for workers to report incidents, procedures for summoning immediate help, and procedures for investigating and dealing with incidents.
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Section 32.0.3 requires employers to assess the risks of workplace violence that could arise from the nature of the workplace, the type of work, and the conditions of work, and to share the results with the joint health and safety committee or representative.
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Section 32.0.6 requires a written workplace harassment program, developed in consultation with the joint health and safety committee or representative, covering how complaints get reported (including when the alleged harasser is the employer or a supervisor), how they get investigated, how confidentiality is protected, and how outcomes get communicated back to the people involved.
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Section 32.0.7 requires that harassment complaints actually get investigated, and that both the complainant and the person accused receive written notice of the results and any corrective action.
Notice what these sections cover: violence and harassment specifically. They don't reach broader psychological hazards like chronic overwork, poor job design, or unmanaged stress. That's a real gap, and it's the gap CSA Z1003 was written to fill voluntarily.
The General Duty Clause
The other piece employers point to is section 25(2)(h), OHSA's general duty clause, which requires an employer to "take every precaution reasonable in the circumstances for the protection of a worker."
Some safety advocates argue this general duty extends to psychosocial hazards broadly, not just violence and harassment. That's a reasonable legal argument, but it's not the same as a specific program mandate. Section 25(2)(h) doesn't tell you what a compliant program looks like, what it has to include, or how often it has to be reviewed, the way sections 32.0.1 through 32.0.8 do. Treat it as a floor, not a checklist.
So What's Actually Optional
CSA Z1003, Psychological Health and Safety in the Workplace, is a voluntary national standard. It gives you a framework for identifying and managing psychological hazards well beyond violence and harassment: workload, role clarity, organizational culture, support for workers dealing with mental illness. None of it is legally required in Ontario.
That doesn't make it optional in the sense of "skip it." A workplace with a legally compliant harassment program can still be psychologically unsafe in ways that show up as turnover, WSIB claims for chronic mental stress, or a Ministry of Labour visit prompted by something you had no formal system to catch. The standard exists because the legal minimum leaves real hazards unaddressed.
Where Employers Get This Wrong
The mistake I see most often isn't ignoring mental health entirely. It's employers building a broad, CSA Z1003-style program while leaving the two things OHSA actually requires, the violence and harassment programs, thin or outdated. A polished wellness initiative doesn't satisfy section 32.0.6. A harassment program that hasn't been reviewed in three years doesn't satisfy section 32.0.1, no matter how good your mental health benefits are.
Get the legally required pieces right first: written, current, developed with your joint health and safety committee, reviewed annually, and actually followed when a complaint comes in. Then build outward toward the broader psychological safety work that CSA Z1003 describes, because it's the right thing to do for your workers, not because a Ministry inspector is going to cite you for skipping it.
A Final Word
If you take one thing from this: don't let "voluntary standard" mean "ignore it," and don't assume "not legally required" means "not required at all." Sections 32.0.1 through 32.0.8 of OHSA are enforceable, specific, and where most employers actually get caught short. Start there. Build out from there.
WorkSafe Sounds helps Ontario employers understand what OHSA actually requires, and where the real risk sits once the paperwork is done. If you're trying to sort out your legal minimum from your best-practice ceiling, you're in the right place.