The Alberta plant at the centre of an E. coli scare is being allowed to resume limited operations.
But the Canadian Food Inspection Agency says no meat will leave the XL Foods meat packer in Brooks until the agency has approved a full reopening.
"Beginning today XL Foods will be permitted to resume limited in-house cutting and further processing under strict enhanced oversight," said Harpreet Kochhar, executive director for the agency's western operations.
"This will allow the CFIA to review in a controlled manner the company's improvements made to all previously addressed deficiencies."
The plant was shut down Sept. 27 during an ever-expanding recall of its beef products across Canada and more than 20 other countries, including the United States.
Mr. Kochhar said the plant has been cleaned and sanitized, and condensation, drainage and ice buildup have also been addressed.
He said no new animals will be slaughtered. The 5,100 carcasses to be processed are already in the plant and have been tested for E. coli. Mr. Kochhar said 99 per cent are free of the bacteria.
"Meat from these carcasses will remain under CFIA detention," he said. "Products will not be allowed to leave the premises until the CFIA has confirmed in writing to the minister of agriculture and agri-food that the plant controls are effectively and consistently managing E. coli risks.
"The CFIA will immediately suspend operations if inspectors note any concerns with the facility's food safety controls."
The union for workers at the packing house has said problems go deeper than that.
Doug O'Halloran told a news conference Wednesday that the pace of slaughter operations forces workers to take shortcuts around cleanliness and puts the health of beef-eating Canadians at risk.
Mr. O'Halloran, president of the United Food and Commercial Workers Local 401, said the processing line at XL Foods moves too quickly.
"You can replace all the aluminum, all the stainless steel you want at the plant, but if you don't give your workers the tools to perform the job properly, we're not going to solve this problem," he said.
Between 300 and 320 carcasses go by workers every hour and employees make between 3,000 and 4,000 cuts a shift. That has resulted in less time in which to make sure knives are sanitized after each cut, the union president said.
Mr. O'Halloran wants a public inquiry into the problems that led to the plant's shutdown.
The CFIA said Thursday it has contacted the union and wants to hear its concerns.
To date, 12 people in four provinces have been infected by a strain of E. coli that has been linked to the plant.
The bacteria was first discovered Sept. 3 in tests by U.S. officials on meat heading south of the border. The U.S. stopped accepting shipments of beef from XL 10 days later. A recall of ground beef was eventually issued Sept. 16 and has been expanded numerous time.