LATEST: All students except one that were involved in a caustic soda accident this afternoon have been released from the Roma Hospital's Accident and Emergency room.
St John's Catholic School has confirmed 37 children in Years' 1 and 2 were taken to Roma Hospital shortly after 12pm.
Eighteen children were taken by ambulance with the remainder taken by their families - in total 57 students and four teachers have been treated either at the scene or at Accident and Emergency.
Immediate first aid was provided and emergency services were called to the school.
Director Diocese of Toowoomba Catholic Education John Borserio said student safety was paramount.
"The safety of children in our schools and our staff is our number one priority," he said.
St John's School Roma principal Nicholas Lynch has been in contact with families of the school students.
Members of the Catholic Education Office are travelling to Roma to provide support to the school community."
UPDATE 3.30PM: THE number of people hospitalised after a caustic soda accident at St John's Catholic school has risen to 37.
Thirty-five of the people hospitalised have been children, and a total of 50 people were exposed to the caustic soda.
Sources have confirmed the chemical accident occurred when a class science experiment went wrong about 12pm this afternoon.
Chemicals were mixed in a plastic coke bottle before it expanded and shattered, exposing the children to the sodium hydroxide.
Sources have also said there will be a full investigations into the accident.
EMERGENCY crews are at the Roma's St John's campus after dozens of children were exposed to sodium hydroxide, otherwise known as caustic soda.
So far, more than 12 students have been taken to Roma Hospital for treatment after exposure to the corrosive chemical.
Police have cordoned off the scene, with officers taking photos for evidence.
Two fire trucks, four ambulance vehicles and three police cars are at the scene.
Roma police Senior Sergeant Barry Winter said it happened in the undercover hall of the school.
At the time it is unsure how the students were exposed to the chemical.
More information to come as it breaks.
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