The fire began at around 7 p.m. at Mécanique Élite on Losch Boulevard, in an industrial park near Highway 116 and Cousineau Boulevard.
More than 40 firefighters were called to the scene initially, joined by another 35 as the evening progressed. .
Two firefighters were sent to hospital with minor burns.
Witnesses reported hearing several small explosions. Authorities on the scene said they were likely caused by small oxygen tanks blowing up or tire rims cracking.
Firefighters expected to spend most of the night putting out the flames as well as dousing neighbouring buildings with water and foam to prevent the fire from spreading.
Late into the night, the thick smoke could be seen from many kilometres away, and the acrid smell of burning rubber hung in the air.
But Longueuil division fire chief Jean-Guy Ranger said the fumes posed no danger to people living in the residential sector of Saint-Hubert.
"[The smoke] is rising, and it's dissipating into the air," Ranger said. "At this time of year, luckily, people have their windows closed, people aren't walking around outside, and the smoke is going up."
Ranger said both Environment Canada and Environment Quebec were notified immediately of the fire.Suggest a correction