INEOS Styrolution is expecting its decommissioning and site closure process will be complete by the end of next year.
In a news release issued on Thursday, the company said it anticipates the work will be finished in the fourth quarter of 2025.
The styrene monomer production site on Tashmoo Avenue has been shut down since April 2024, after orders were placed on the facility in response to members of Aamjiwnaang First Nation feeling ill due to elevated levels of benzene emissions.
In June, INEOS announced plans to permanently close the site by June 2026.
At the end of August, the company adjourned its appeal of the orders it was seeking to receive more time to install abatement technology to mitigate benzene emissions.
INEOS CEO Steve Harrington confirmed on October 24 the facility will not restart.
"Since announcing the difficult decision to permanently close our Sarnia site, we have conducted an extensive assessment to determine the operational viability of restarting the site on a temporary basis," said Harrington. "Ultimately, the conclusion of the assessment was that temporarily restarting the site is not operationally feasible or economically justifiable."
While a specific date for the site closure has yet to be determined, INEOS said the decommissioning and wind-down process is expected to be complete early in the fourth quarter of 2025.
"We are now focused on conducting a safe, responsible, and compliant closure process and supporting our employees, contractors, customers, and partners, including offering transition support for impacted employees. I want to extend my deepest appreciation to our Sarnia team for their contributions to our business over the years."
The company has said the Sarnia site employs 80 people and a large number of contractors.
Benzene removal at the site wrapped up earlier this month.
Aamjiwnaang First Nation had moved some residents in designated zones around the plant out of the area as a precaution while the removal work was completed.