NOVA Chemicals reported a release of crude oil at its Corunna facility on Wednesday.
In an email, Communications Consultant Meaghan Lawrence said the event was isolated quickly.
"There was no offsite impact and personnel are investigating and managing on-site activities," said Lawrence.
She said the company shared an information update on the Community Awareness and Emergency Response Line.
An all-clear had sounded by 1:30 p.m.