Some homes and businesses in Wheatley have been evacuated.
According to Chatham-Kent Fire, crews responded to 15 Erie Street North for reports that the hydrogen sulfide detector had activated just after 8 a.m.
Firefighters from Wheatley and Tilbury are currently on scene and the Windsor Fire Hazmat team is on route.
Erie St North between Talbot Street and Elm Street and Talbot Street east between Erie Street to Little Street are closed off.