Exhibition Arena in Guelph was evacuated Saturday afternoon because of an ammonia leak.
Alan Farquharson, Guelph’s acting Platoon Chief, says it was a small leak but it was enough to set off the detection system alarm.
Residents were asked to move 500 metres away from the building while firefighters investigated.
A Hazardous Materials Response Team was also organized as a precaution.
The leak was soon sealed by a refrigeration technician.
No one was injured.