What makes a workplace investigation "appropriate"?

By George Waggott, founder, George Waggott Law

For nearly a decade, Ontario employers have been required under the Occupational Health and Safety Act (OHSA) to investigate workplace harassment complaints in a manner that is "appropriate in the circumstances." Despite this statutory obligation, there has been relatively little guidance until now on what that standard actually requires.

That changed with the Ontario Labour Relations Board's June 2026 decision in Alyssa Gassi v. The Corporation of the County of Lambton, 2026 CanLII 64801. This ruling is one of the first to provide detailed direction on what constitutes an appropriate workplace harassment investigation under the OHSA and offers valuable guidance for employers, human resources professionals, and workplace investigators.

The case involved a former municipal prosecutor who alleged workplace harassment and later challenged the adequacy of her employer's related investigation. Although the Board dismissed her reprisal complaint, which claimed that her termination was the result of her harassment complaint, the Board reached a different conclusion regarding the investigation itself. In particular, the Board found that the employer had failed to conduct an investigation that was "appropriate in the circumstances," even though it had completed an internal review of the complaint.

The Board emphasized that an appropriate investigation is primarily about process, not outcome. An investigation is not considered adequate (and thus “appropriate in the circumstances”) simply because the investigator concludes that harassment did not occur. Instead, employers must demonstrate that the investigative process was fair, thorough, and proportionate to the circumstances. The specifics will depend upon each case, based on the nature of the complaint and the related allegations.

One of the Board's principal concerns was that the employer’s investigator who reviewed Ms. Gassi’s complaint interviewed only one witness despite several individuals being identified as having relevant information. The investigator also failed to explain why additional interviews were unnecessary, making it very difficult to understand or challenge the rationale for the findings of the investigation. Equally important, the complainant was never given an opportunity to respond to information gathered during the investigation before findings were reached. These procedural shortcomings led the Board to conclude that the investigation did not meet the statutory standard as required by the OHSA.

The decision also offers practical guidance for employers conducting internal investigations, even if not directly involving workplace safety. The Board confirmed that an external investigator is not mandatory in every case - internal investigators can conduct appropriate investigations provided they understand the OHSA's workplace harassment provisions, are familiar with the employer's policies, and ideally possess investigation experience. These same principles will apply to investigations more generally. Employers should therefore ensure that managers or Human Resources personnel who are assigned investigative responsibilities receive appropriate training before handling complaints and conducting investigations.

Importantly, the Board rejected the notion that every investigation must follow a rigid checklist. An appropriate investigation does not necessarily require every allegation to be explored or every identified witness to be interviewed. However, where investigative decisions are made, including a decision to limit interviews or narrowing the scope of the investigation, they should be supported by clear reasoning that can withstand later scrutiny.

For Human Resources professionals and business owners, the message is clear: documenting the investigative process is just as important as documenting the conclusions. Decisions about who was interviewed, why certain evidence was considered sufficient, and how both parties were given a meaningful opportunity to participate should all be carefully recorded.

The Gassi decision reinforces that workplace investigations are not merely compliance exercises. They are fundamental to maintaining employee trust and meeting an employer's legal obligations. By focusing on procedural fairness, investigator competence, and thoughtful decision-making, employers will be better positioned to demonstrate that their investigations are truly "appropriate in the circumstances". This will be especially important if their process is ever challenged before the Board or other decision makers.