Can supply teachers, who are merely contract and casual employees, benefit from the right to take preventive withdrawal conferred by Quebec’s Act respecting occupational health and safety (Act) and thus receive the resulting income replacement indemnity? According to a recent ruling by the Supreme Court of Canada in Dionne v Commission scolaire des Patriotes, the answer is yes.1


In 2006, Marilyne Dionne was added to the Commission scolaire des patriotes (School Board) list of about 500 supply teachers. Once she was on the list, her services were requested frequently through the call centre in charge of handling replacements. 

In September of that same year, Ms. Dionne learned that she was pregnant. A few weeks later, her doctor told her that she was vulnerable to viruses that could harm the fetus. Because the classroom posed a risk for her health, her doctor completed two certificates for the preventive withdrawal and re-assignment of Ms. Dionne.   

Ms. Dionne provided the certificates to Quebec’s occupational health and safety commission (CSST), which informed her that if she received a supply contract, she would be eligible for preventive withdrawal as part of the “For a Safe Maternity Experience” program. Soon afterwards, the School Board call centre requested her services and the CSST told her that she was entitled to take preventive withdrawal and receive the related indemnity.  

The School Board contested the CSST’s decision and won its case before the province’s occupational injuries commission (CLP), which concluded that Ms. Dionne was ineligible for preventive withdrawal because withdrawal was only available to “workers” as defined in the Act. The CLP reasoned that as Ms. Dionne was not able to go into the school owing to the health risks identified by her doctor, she could not perform her duties as a supply teacher, which meant that no contract had been formed; without a contract, Ms. Dionne was not a “worker” and therefore not protected by ss. 40 and 41 of the Act.  

The Superior Court upheld the CLP’s decision, finding it to be reasonable, and the Court of Appeal disallowed an appeal of the Superior Court decision, thereby confirming that Ms. Dionne was not entitled to the sought indemnity.

However, as the Court of Appeal decision had a dissenting judge, Pierre J. Dalphond, J.A., an appeal was brought before the Supreme Court of Canada, which unanimously allowed it and thereby confirmed that Ms. Dionne was entitled to access the protections of the Act.  

The decision

In its decision, the Supreme Court begins by reviewing the Act’s history and adoption, referring, among other things, to a worker’s right under s. 12 of the Act to refuse unsafe work.  After this brief review, the court points out that the Act “gives workers the necessary tools by which to safely and confidently assert those rights.” According to the court, one of those tools is preventive withdrawal, introduced to prevent the discriminatory exclusion of women from the workplace based on pregnancy and to ensure their right to work in a safe environment.

On this basis, the Supreme Court considers the issue of whether Ms. Dionne, a supply teacher, can be considered a “worker” as defined in the Act, in that a contract of employment was formed despite her inability to go to the workplace and perform her supply teaching contract.

In the Supreme Court’s opinion, a contract was formed when Ms. Dionne accepted the offer to supply teach presented to her while she was pregnant, when her doctor had warned her about the risks to her health and that of her fetus. At the moment the contract was formed, Ms. Dionne was deemed to be at work and therefore a worker as defined in the Act.

In this regard, the Supreme Court points out that Ms. Dionne’s pregnancy was not an incapacity that prevented her from performing the work; she was prevented from performing the work by the dangerous workplace. For these reasons, the protections set out in the Act were available to Ms. Dionne, despite her contractual status.  

The Supreme Court held that excluding pregnant contract workers ignores the legislative purpose of the Act and would put these women in the “untenable” position of having to choose between entering into an employment contract in order to work and protecting their health and safety.  


This decision by the country’s highest court will no doubt have a significant impact on Quebec teaching staff. The case at hand is proof of this: the Commission scolaire des Patriotes had over 500 teachers on its supply teacher list.

Finally, it seems to us that this decision confirms the strong trend towards a broad and liberal interpretation of this Act. This perspective, here corroborated by the Supreme Court of Canada, is consistent with a desire to see the Act achieve its purpose. The reasons given by the Supreme Court suggest that it had little tolerance in this case for what it qualified, without openly saying so, as an injustice.