Arbitration Decisions Shed Light on WSIB Bar and Document Disclosure

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Introduction

Two recent arbitration decisions from Ontario and British Columbia highlight important lessons for unionized employers dealing with workplace safety incidents and employee discipline. Both cases turned on procedural issues: the scope of remedies a union can pursue in the face of statutory limits, and the extent of documentary disclosure available when discipline is challenged. While the subject matter is different, the common thread is clear: employers should expect arbitrators to look closely at statutory frameworks and fairness principles when deciding how far grievances can go.

Kingston Health Sciences Centre v. Ontario Public Service Employees Union, Local 4106, 2025 CanLII 67201

What Happened

The Kingston Health Sciences Centre (“KHSC”) was subject to a series of grievances after a construction project in its Core Laboratory led to employees’ exposure to toxic dust. On August 10, 2023, a wooden countertop containing phenol and formaldehyde resin was cut and resized, releasing dust that allegedly caused irritation and other symptoms.

One employee reported muddy eyes, coughing, vomiting and a sore throat, though she did not apply for Workplace Safety and Insurance Board (“WSIB”) benefits. Another did apply for WSIB benefits and was approved, though she did not describe her symptoms. No one missed work.

The employer had placed only a tarp to contain the dust and provided no personal protective equipment to employees. The Ontario Public Service Employees Union (“Union”) alleged that the KHSC delayed providing the required safety data sheet for three weeks, leaving staff uncertain about what they had been exposed to.

The Union filed grievances alleging violations of the Occupational Health and Safety Act (“OHSA”) and the collective agreement.

The Arbitration

The KHSC raised a preliminary objection and argued that the Workplace Safety and Insurance Act (“WSIA”) barred the grievances because section 26(2) extinguishes all rights of action “for or by reason of” a workplace accident. In its view, each of the Union’s claims boiled down to personal injury, which fell within the WSIA scheme.

The Union countered that it was seeking broader remedies, including damages for unsafe work conditions, mental distress and breaches of the OHSA and the collective agreement, along with declaratory relief to deter future misconduct.

Arbitrator Colin Johnston agreed with the KHSC on the damages point. Applying the framework from the decision in Monk,^[1] the arbitrator found that all of the Union’s claims – whether framed as unsafe work practices before the incident or delays in providing information afterward – were tied directly to the August 10 exposure. In substance, they were personal injury claims barred by the WSIA.

However, the arbitrator did not accept the KHSC’s argument that the grievance was moot. He emphasized that health and safety obligations are ongoing, and a declaration that the KHSC breached its obligations could serve an important deterrent purpose. The fact that the Ministry of Labour chose not to issue an order did not extinguish the grievance. As a result, the arbitrator allowed the grievance to proceed, enabling the Union to pursue declaratory relief.

Takeaways

For Ontario employers, the decision is a reminder of the broad scope of the WSIA’s “bar” on civil and arbitral damages claims tied to workplace injuries. Even when unions try to frame grievances as breaches of the collective agreement or occupational health and safety obligations, arbitrators will look to substance over form.

That said, employers should not assume that grievances disappear simply because the incident has ended. Arbitrators may still grant declaratory relief to underscore ongoing health and safety obligations such as claims of bullying or harassment. Employers need to take those obligations seriously in real time, because declaratory findings – while not monetary – can still have reputational and labour relations consequences.

Health Employers’ Association of British Columbia (Vancouver Island Health Authority) v. British Columbia Nurses’ Union, 2025 CanLII 57035

What Happened

An employee (the “Grievor”) was terminated following allegations of bullying, harassment and discrimination. The Health Employers’ Association of British Columbia (the “Employer”) relied on two investigation reports prepared by a third-party investigator, which concluded that the misconduct had occurred. Based on those reports, the termination occurred in November 2023.

The British Columbia Nurses’ Union (“Nurses’ Union”) grieved the termination, arguing that the Grievor was innocent of the allegations and had been treated more harshly than three other employees accused by the same complainant. Those three employees were disciplined but not terminated. The Nurses’ Union alleged that the Grievor was treated differently because of his age and proximity to retirement.

Ahead of the hearing, the Nurses’ Union sought extensive documentary disclosure. They asked for complete investigation files, including terms of reference, plans, correspondence, draft witness statements and internal Employer communications about the investigations and discipline decisions. They also asked for documents relating to the discipline of the three other employees in question. Finally, they requested internal correspondence about the Grievor’s age or retirement plans. The Employer resisted, referring to the requests as a fishing expedition that went beyond what was needed to arbitrate the grievance.

The Arbitration

Arbitrator Randall J. Noonan took a middle ground. He found that the investigation materials were central to the Employer’s decision to terminate and therefore had to be disclosed. Since the Employer relied on those reports, the Nurses’ Union was entitled to examine the underlying files to test their reliability.

The arbitrator also agreed that the Nurses’ Union was entitled to documents concerning how the three other employees were treated. Consistency of discipline is a well-established principle under the Wm. Scott^[2] framework, and comparing the Grievor’s case to others accused of similar misconduct was directly relevant.

However, the arbitrator rejected the Nurses’ Union’s request for internal correspondence about the Grievor’s age or retirement. He found there was no evidentiary basis for suggesting that age discrimination played a role in the decision to terminate, so ordering disclosure of those materials would amount to a fishing expedition.

In the end, the arbitrator granted disclosure of investigation files, internal correspondence about the disciplinary process and documents concerning the three other employees, but denied the request for retirement-related records.

Takeaways

This decision is notable for the breadth of disclosure ordered. While arbitrators often require employers to provide investigation reports if they form the basis for discipline, the ruling here went further by also compelling disclosure of internal correspondence and documents related to the discipline of other employees. That reach may come as a surprise to employers, given that such materials are usually treated as internal management deliberations.

For employers, the concern is that relying on an investigation report may now open the door to more extensive disclosure obligations than anticipated. Internal communications that were once thought to be protected could end up before the arbitrator if they are found to be “material” to the discipline decision.

Second, arbitrators are attentive to consistency in discipline. If multiple employees are accused of similar misconduct, employers should be prepared to explain and document why different penalties were imposed. Disparities – especially where one employee is terminated while others are not – will invite closer scrutiny.

At the same time, the case shows that arbitrators are mindful of proportionality. They will not grant unions carte-blanche access to internal communications without a clear basis. Employers can resist disclosure requests that are overly broad, speculative or not tied to the core issues in dispute.

Conclusion

Employers are regularly faced with broad and undefined grievances, which often expand once the grievance moves to arbitration. Coupled with what is now a practice by unions to ask for broad and often irrelevant documentary production, employers are facing further procedural and evidentiary hurdles in defending against allegations of a breach of a collective agreement.

Both cases outlined above illustrate how arbitrators attempt to balance statutory frameworks with fairness in the workplace. In Ontario, employers cannot escape health and safety obligations even where damages claims are barred by the WSIA. In British Columbia, employers relying on investigation reports must expect transparency in disclosure and be ready to justify differences in discipline among employees.

For employers across Canada, the lesson is the same: compliance with statutory obligations and procedural fairness is not optional. Taking proactive steps in safety, documentation and consistency of discipline is the best way to reduce the risk of adverse arbitration outcomes. At the same time, careful consideration of what documents are produced during an investigation is critical, as those documents may be ordered in the event that a grievance moves to arbitration.

The Workplace Law Group at Aird & Berlis LLP provides strategic labour advice to help employers navigate union-related challenges, from resisting certification to managing collective bargaining and arbitration. Please contact the authors or a member of the team if you have any questions or require assistance.

[1] Ontario Public Service Employees Union v. Ontario (Community Safety and Correctional Services and Ministry of Children andYouth Services), 2010 CanLII 28621 (“Monk”).