An explosion occurred late Wednesday at Aldex Chemical, a chemical-product factory in Granby, about 80 kilometres east of Montreal.
Firefighters got a call at around 5 p.m. about a blast at the factory on Laurent Street.
Local media reported the presence of thick smoke that could be seen from kilometres away.
No one was injured in the explosion.
Nearby buildings were evacuated, as 3,600 kg of polystyrene burned in the fire.
Aldex Chemical employs 18 people, and has been operating for 34 years.
It specializes in the manufacturing of resins and synthetic rubber that is used in waste-water treatment plants.
The plant has three types of dangerous materials: sulfuric acid, ammonia and styrene.
Urgence-Environnement — the province’s environmental emergency service — was at the plant last week after a chemical spill in the storm sewers.
It was the third time the agency intervened at the company in the last two years.