A mysterious gas near a school science lab has caused students to vomit and forced an evacuation. Eight students were taken to hospital.
A mysterious gas near a school science lab has caused students to vomit and forced an evacuation. Eight students were taken to hospital.

Mystery odour leaves school students coughing and vomiting

A mysterious substance near a science lab in a Sydney high school has caused students to cough and vomit and forced an evacuation of the surrounding classrooms.

One parent criticised the school,for playing down the seriousness of the incident, after staff told them emergency services were present to "conduct an assessment".

Students at St John's Park High School in Greenfield Park, in Sydney's west, began being affected by the mystery substance just before 11am on Thursday.

The school science labs and library were the epicentre of the illness.

A Fire and Rescue NSW spokesman said dozens of students and some teachers suffered symptoms including nausea, vomiting, sore throat and headaches.

The school evacuated people from the science labs, library and surrounding classrooms.

St Johns Park High School in Greenfield Park.
St Johns Park High School in Greenfield Park.

Ambulance crews, firefighters and police attended the school, with paramedics assessing 32 students and 10 adults, and taking eight students aged between 13 and 15 to local hospitals at Liverpool and Fairfield.

Two teachers refused transport to hospital but said they would seek medical attention if their symptoms required it.

Firefighters were not able to find the source of a gas leak or any evidence of a substance that may have induced the mass illness.

Fire and Rescue NSW Acting Superintendent Rob Jansen said the source of the illness remained a mystery.

"We were called to a gas leak or a spill of some sort in the science lab," he said.

"They searched both the science lab and the library and were unable to find any source of a gas leak or any spill of any substance."

The school texted parents: "Parents - Do not be alarmed that Emergency Services are at SJPHS they are conducting an assessment. There is no emergency and more information will be provided."

However a parent with a child at the school said the school tried to downplay the seriousness of the incident.

"They sent home a message to parents saying there was an incident at the school, don't panic, the services were there just doing an assessment."

"When my daughter came home, she said she was in the classroom next door and the teacher came in and said 'evacuate, evacuate'."

"Apparently there were kids vomiting, coughing and choking."

"This all happened this morning and the school didn't notify parents until after 12pm today."

An Education Department spokesman said teachers noticed "a suspected odour" during classes in the morning.

"No one was injured but some students and staff presented with mild symptoms such as coughing and nausea. A few students were sent to local hospitals as a precaution," he said.

"The incident was reported immediately to local emergency services, who attended and cordoned-off the areas involved who proceeded to check these areas thoroughly."