INEOS Styrolution says exhaust fumes caused a reported increase in emissions earlier this week, and was unrelated to benzene stored at the Sarnia plant.
A notification advising residents of above normal emissions was issued on Wednesday through the Sarnia-Lambton Alerts system.
An update by INEOS to Sarnia News Today on Friday said the matter was "thoroughly investigated."
"The source of the emissions has been identified as exhaust fumes from an on-site forklift truck and is unrelated to any benzene stored at the Sarnia plant," read the company's emailed statement. "The updated benzene emissions limits, introduced by the [Ministry of the Environment, Conservation and Parks] and [Environment and Climate Change Canada] in April 2024, allow for heightened sensitivity in monitoring, meaning even low levels can trigger alarms."
INEOS again emphasized that benzene stored at the Tashmoo Avenue facility is not the sole source of emissions within the Sarnia area.