There were two hydrocarbon releases Monday morning at Sarnia's Imperial manufacturing site.
Plant sirens sounded twice, around 7am and again at 11:15am.
Imperial spokesperson Kristina Zimmer says the company's emergency response crews isolated a second hydrocarbon release late Monday morning. She says the incident was separate from an earlier release at 7am but, the source, in both incidents was isolated within 30 minutes and the all-clear has been issued for both.
In each case, on-site personnel sheltered in place as a precaution while monitoring and other response activities took place.
Air monitoring was ongoing and the Ontario Environment Ministry and Chemical Valley Emergency Coordinating Organization (CVECO) were both notified of the incidents.
Imperial is investigating the cause of the two hydrocarbon releases.
-With files from Josh Boyce
