A group of fourth grade students from Deception Bay North School have fallen ill after mistaking blue coloured crystals for popping candy.
The chemical found in the crystals consumed was Mystical Fire, used to alter the colour of open flames.
Paramedics were called to the Queensland school after students experienced nausea, vomiting and burning throats.
Four students have been hospitalised, while twenty one others were treated at the scene.
The Department of Education has said the school is currently investigating how the mix-up occurred.
“The principal is investigating the cause of the incident and if necessary, will take appropriate disciplinary action in line with the school’s Responsible Behaviour Plan for Students,” a statement said.
Queensland Police said the substance was probably brought onto school grounds by students.
“It’s suspected it was introduced into the school through students. The school is conducting their own investigation and they’re yet to determine exactly how it was brought in,” Inspector Lee Jeffries told 9 News.