UPDATE: Twenty-four students and a teacher were treated by paramedics after a chemical incident at a Darling Downs school.
Emergency services were called to Millmerran P -10 State School just after 10am to reports of the chemical incident as a result of a science experiment involving the use of sulphur gas.
Queensland Fire and Emergency Services entered the school in breathing apparatus and conducted atmospheric testing before ventilating the area.
A Department of Education and Training spokesperson said the incident took place in a science laboratory and Queensland Fire and Emergency Services was called as a precaution.
"Firefighters conducted atmospheric testing and did not detect any dangerous chemicals in the classroom," the spokesperson said.
They said the parents of all students were contacted and the affected area was ventilated with large fans to avoid further safety concerns or disruptions.
Queensland Ambulance Service senior operations supervisor Glen Barron said the teenagers were all taken to Millmerran Health Service in a stable condition, with many returning to school the same day.
"A couple of the children had been affected by some fumes, so off-gasses from one of their science experiments," he said.
"So we attended to that and as it progressed we gradually had more students who presented with some minor symptoms."
Mr Barron said symptoms included nausea and light headedness and one girl was treated for pre-existing asthma.
EARLIER 11AM: Twenty-four people are being treated by paramedics after a Hazmat incident at a Darling Downs school.
Queensland Fire and Emergency Services was called to Millmerran State School on Simmons St just after 10am.
A QFES spokeswoman said one truck was on scene and a team of firefighters were sent into the affected part of the school in breathing apparatus.
She said firefighters conducted atmospheric testing and did not detect any chemicals.
They are now ventilating the area using big fans.
A Queensland Ambulance Service spokeswoman said 24 teenagers were currently being assessed by paramedics due to possible reported chemical inhalation.
It is not known if the patients are students.
EARLIER 10.15AM: Firefighters are en route to a Hazmat incident at a Darling Downs school.
Queensland Fire and Emergency Services received the call about the incident at Millmerran State School about 10.10am.
Initial reports suggest there has been inhalation of sulphur gas as a result of a sulphur rock being heated.
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