Dozens of firefighters, at least 70 in total, battled a blaze at Atlantic Packaging near Midland Avenue and Progress Avenue Monday around 4 p.m.
Firefighters were concerned that the fire, in an industrial building just south of Highway 401, would cause the structure to collapse due to extreme heat.
But they were later able to get the fire under control and said there wasn't any structural damage to the building. The fire was contained to only one corner of the building.
The fire most likely started in loose cardboard outside the building and moved inside, where bales of tightly-packed cardboard provided fuel for the fire, Division Commander Lorne Buckingham told CP24.
"Once it gets inside the bales, they have to be broken up to extinguish it," said Buckingham.
Fire crews were able to work with employees at Atlantic Packaging who used machinery to move and break up the bails and then douse them with water.
Firefighters also reported that poor visibility, caused by plumes of smoke, made the task of fighting the fire more difficult, as did heavy traffic in the area, which delayed the response of some of the fire crews.
The fire was mostly extinguished by 7:30 p.m.
