A Federal Court judge has struck down a proposed class-action lawsuit filed on behalf of current and former Canadian military members alleging exposure to “dangerous levels of toxic mould” on Canada’s warships.
Plaintiff Félix Dunn claimed the Canadian Armed Forces was aware, or should have been aware, of the presence of harmful mould on its naval vessels, and was therefore negligent in maintaining the ships and preventing foreseeable harm in the workplace.
Dunn was stationed aboard HMCS Vancouver, a Halifax-class frigate and one of the largest vessels in the Royal Canadian Navy, from June to December 2016, when he started complaining of chills, fever, fatigue and a “burning and tightness in his chest” accompanied by a cough, the court heard.
He later “discovered what he believed to be black mould growing from the fittings in the pipes on the ship,” Justice Cecily Strickland wrote in her summary of the case. “Shortly thereafter he was diagnosed with exercise-induced asthma, sleep apnea, and chronic rhinitis.”
Dunn, who was released from the military in 2022, told the court that although he was treated with antibiotics while serving on the frigate, he never fully recovered. He continues to suffer “violent swings in temperature,” breathing troubles and a compromised quality of life, he said.

Dunn would go on to claim various disability benefits through Veterans Affairs Canada, while also filing the claim for a proposed class-action case on behalf of all current and former CAF members who served on naval vessels from January 2000 onwards.
In early 2021, Veterans Affairs awarded Dunn partial disability benefits for his cough and chronic rhinitis, confirming these injuries arose out of his service to the country. He also won a medical release from the CAF for his duty-related injuries, and by the following year had collected more than $150,000 in additional payments for pain and suffering, according to the court.
The Attorney General of Canada, however, in moving to strike the class-action claim, argued that Dunn had already been sufficiently compensated for his injuries through Veterans Affairs.
The judge agreed.
“In my view, the plaintiff’s claim in this case relies on the same factual basis that led to compensation being paid to him by VAC (Veterans Affairs Canada). That is, the presence of mould on a CAF ship to which the plaintiff was exposed in the course of his CAF duties causing him injury,” Strickland wrote in her April 9 decision.
“Thus, the compensation paid or payable to him is a bar to the action against the Crown because it is made on the same factual basis as the plaintiff’s action. More specifically, the compensation was given in respect of the identical injury or disease which forms the basis of the claim.”
‘Double recovery’
The federal Crown Liability and Proceedings Act prevents the co-called “double recovery” of compensation from the federal government for claims arising form a previously compensated misconduct, according to a 2002 Supreme Court of Canada decision cited by the judge.
Another barrier to the success of Dunn’s claim was that he didn’t file grievances about the presence of mould or other toxins while still in uniform, the judge noted.
The attorney general argued Dunn’s complaints were essentially workplace grievances that should have been raised through the military’s dispute resolution system to be investigated and resolved before resorting to a class-action proposal.
Here again the judge sided with the federal government.
“I agree with the AGC (Attorney General of Canada) that the court should decline jurisdiction given the comprehensive CAF dispute resolution scheme,” Strickland wrote.
“There is also no evidence that the plaintiff sought to grieve any matter related to workplace safety, injury or illness while serving in the CAF, and he does not assert otherwise.”
In granting the federal government’s motion to strike down the class action proposal, the judge ruled Ottawa was entitled to recover its costs for the proceedings, which the attorney general declined.