Health authorities said the students, four of whom received treatment in the hospital, are from Victoria, New South Wales and Queensland. They are all staying at the one location.
The students from Queensland are all in year 7 at the St. Peters Lutheran College at Indooroopilly.
A public health team remained on site to make sure the outbreak does not spread any further.
In a separate incident, another 50 children were treated by ambulance officers after suffering reactions against an unidentified chemical substance at a primary school in Melbourne's south-east. Two of these children were taken to the hospital.
The children, who are all from the ISIK community school in Chapel Road in Keysborough, had earlier complained of symptoms including eye irritation and minor respiratory distress.
School authorities called Metropolitan Ambulance Service paramedics.
The Country Fire Authority (CFA) also responded to the scene to determine the cause of the irritant which, according to CFA spokesman Peter Boicovitis, may have been caused by chemicals sprayed in the area.
The school is reportedly adjoining a nursery and farmland.
