A Harrogate school was the scene of a controlled explosion.
Ashville College saw drama on Friday morning, November 4 when the bomb squad was called out from Catterick Garrison.
Once the controlled explosion was successfully carried out it was revealed that the scare had started in Ashville's science department.
A spokesman for the private school said: "The school was contacted by CLEAPSS (the Consortium of Local Education Authorities for the Provision of Science Equipment). The chemical 2,4-dinitrophenylhydrazine was identified as being stored in the Ashville chemical store and we were given advice on how to manage its removal safely.
"The school has followed all the official advice given and this morning, a police officer and two members of the Army Bomb Disposal Team from the Catterick Garrison arrived to expedite the disposal of the chemical in question. This has now been concluded safely and without incident.
"The disposal took place at 11.00 am on the Junior cricket field when the chemical was destroyed via a small controlled explosion. The whole operation took just 15 minutes and was conducted in a safe and measured environment."
"The Police and Bomb Disposal Unit ensured the safety of all pupils and staff on site to which end all staff and pupils across the College were retained indoors until the procedure had been completed and the all clear given."