A lab technician noticed that the flask was 'not in its expected condition' whilst she was cleaning out a storeroom on Friday lunchtime (October 3).

Moments after she left to seek advice the flask apparently exploded, causing a small fire.

Automatic fire alarms sounded and the building was evacuated.

There were no pupils in classes at the time, and no one was hurt in the incident, the school said.

Fire services treated the explosion as a chemical incident, deploying protective clothing and decontamination procedures.

The school's head master, John Franklin, said: "Although this could have been a dangerous situation, the steps in our Emergency Plan were put into action and worked very successfully.

"No one was hurt in the process and the damage to the laboratory area was limited.

"We are most grateful for the prompt attendance and attention given by West Sussex Fire Brigade."

Read this week County Times for a full report.

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