A chemical leak at Sunnybrook Hospital forced some procedures to be rescheduled, but no widespread evacuation was required.
Toronto Fire were first called to the scene on Sunday when a chemical leak was reported in the basement of the hospital.
Fire crews made sure monitoring was in place and determined there was no emergency. They told staff if there were concerns of rising levels to call them back.
Toronto Fire was called back again Monday as the monitors were reading a rising level of chemicals.
An evacuation was ordered in one area of the basement of the hospital, but no patients have been moved or evacuated.
Four staff members were assessed in the emergency room as a precaution but did not show any symptoms. Fire crews have isolated the area and there is no danger for anybody.
Sunnybrook tells CityNews in a statement, a small number of procedures were rescheduled on Monday and more information is expected on Tuesday.