More than 20 Richmond Hill students needed medical treatment at their school and in hospital because of noxious fumes.
Around noon Friday, paramedics were called to Roselawn Public School on Carrville Drive, near Bathurst Street after 22 students became ill.
Ten of them were treated at the scene and 12 others were taken to a local hospital. York EMS says all will recover.
Fire officials said the children were overcome by caulking fumes from the school’s windows.