Arlanxeo reported a small fire just before noon Monday at its Sarnia site.
North American Corporate Communications Manager Caitlin Leopold said in a statement that residual material auto-ignited when an exchanger was opened during routine maintenance at the Olefins Unit.
The Sarnia fire department was called under Chemical Valley Emergency Coordinating Organization protocol and helped site personnel put the fire out.
Leopold said there were no injuries or damage reported to the unit.
She said air monitoring was being conducted during the incident and no contaminants were detected along the fenceline.
Operations at the Sarnia site were continuing as normal.