Imperial Oil personnel have given the all clear following a report of a toxic vapour release at their Sarnia refinery.
Imperial officials say two hydrogen sulphide (H2S) monitors activated, sounding an alarm within the site at around 6:05pm on Thursday. However, no leaks were discovered and air quality monitoring has not detected any levels of H2S or hydrocarbon. The all clear was issued at 6:15pm.
There were no injuries as a result of the incident.
The Ministry of the Environment has been notified, and Imperial officials are conducting an investigation into what caused the monitor alarms to activate.
