A pulp mill on Vancouver Island that supplies American producers with materials to make surgical masks and other medical supplies has been dragged into a trade dispute between Canada and the United States, after President Donald Trump signed an order to restrict exports of personal protective equipment needed to respond to the COVID-19 pandemic.

Harmac Pacific, whose facility is located in Nanaimo, B.C., produces a type of pulp that is used by U.S. manufacturers to make products that include paper gowns, surgical masks and caps, some of which are then shipped to Canada. The company says one of those customers recently doubled its order, prompting the facility to shift its production to focus on pulp for medical-grade paper.

The B.C. facility does not supply 3M or any other company with materials used to make N95 respirator masks, which have been targeted by Mr. Trump as he seeks to keep a range of personal protective equipment, including surgical masks, gowns and gloves, from leaving the United States. But Harmac has been singled out as an example of how dependent the two countries are on each other for medical gear and why any interruption could end up constraining supply in both countries.

Story continues below advertisement

Company president Levi Sampson said restricting trade of medical supplies across the border won’t help anyone.

“This is a global issue and supply chains, especially of medical supplies making their way to the front lines, should be everybody’s priority,” Mr. Sampson said in an interview.

“I don’t think it’s productive for medical supply chains to stop.”

Mr. Sampson’s plant is the only producer of a pulp called K10s, which is made with western red cedar and produces a soft fibre that can be used in medical products. Other pulp mills around the world have their own blends that can be used for the same purpose.

Mr. Trump described medical supply exporters in the United States as “unscrupulous actors and profiteers” and said his government would ensure the country has the equipment that it needs.

Prime Minister Justin Trudeau pushed back against Mr. Trump, but said on Saturday that Canada wouldn’t retaliate.

The COVID-19 pandemic has prompted fears that Canadian hospitals could run out of protective equipment and other supplies if they are swamped by a surge of patients, leading federal and provincial governments to promise to ramp up domestic production to meet demand.

Story continues below advertisement

It’s not clear whether any Canadian manufacturer has the capacity to turn Harmac’s pulp into masks and gowns. Mr. Sampson said it’s a specialized and highly regulated industry, adding that all of his company’s K10s customers are in the United States.

“You would have to have somebody that’s able to make those final products here," he said.

Mr. Sampson said Deputy Prime Minister Chrystia Freeland called him on Saturday. She congratulated the company for its work making pulp for medical-grade paper and didn’t focus on the trade dispute or possibility of supplying Canadian manufacturers, according to Mr. Sampson.

A day earlier, B.C. Health Minister Adrian Dix also mentioned Harmac as he condemned the actions of Mr. Trump.

“I would note that raw materials that are involved here also come from Canada," Mr. Dix said on Friday.

“We live in a community that’s strongly linked together and we hope that Canada and the United States can find a solution to this.”

Story continues below advertisement

Mr. Dix warned that retaliation could make the situation worse.

The Harmac mill employs more than 300 people, who are all working to meet demand for the company’s medical-grade pulp. Staff who can work from home are doing that, and the company has increased cleaning and spaced out workers in the mill, he said.

The Harmac Pacific mill almost closed more than a decade ago when its former owner, Pope and Talbot, went into bankruptcy. The mill’s workers and its union brought on private investors to purchase the facility and keep it running.