A MYTHOLMROYD school was shut for half a day this week after a hazardous chemical went missing.
Around 150g of Thermite Ignition Powder - which can explode if exposed to moisture - was taken from a science laboratory at Calder High School.
Police were alerted to the disappearance of the dangerous mixture, which is used for science demonstrati
ons, at 4.10pm on Monday and began a desperate search to find the container.
It was finally located yesterday morning at around 10.30am.
A spokeswoman for the school said: "We have retrieved the substance. The headteacher is delighted it has been found and would like to thank all of the staff for their help in this matter."
They refused to reveal any further details about the discovery stating it was now a police matter.
A police spokeswoman confirmed: "We have been informed by the school that the chemical has been found. Inquiries are ongoing."
Speaking on Monday night, Inspector Mark Strother said the powder posed a significant danger to the public and advised people not to touch or swallow the mixture, which is also poisonous, but to call them immediately.
The Thermite Ignition Powder is in a 500g brown bottle containing around 150g of the chemical. It bears a label reading General Purpose Grade and the trade name Fisher Scientific.
The chemical is usually locked away but was being used in a class experiment when it went missing.
Headteacher Stephen Ball said he had also been concerned the chemical could cause serious harm to someone.
"The substance is potentially unstable and can burn at very high temperature; it carries the risk of explosion."
The school building was searched on Monday night, with staff remaining on-site to help, and remained closed Tuesday morning while a more detailed search of the premises and grounds was carried out.
Teachers hunted through bins, skips and cupboards.
Staff and students with access to the lab were interviewed.
And Mr Ball said students will be spoken to and made aware of the dangers of the chemical and a letter to parents will be sent out.
"We decided the most responsible thing to do was to make people aware that the chemical is missing from school."
He said the chemical is used to demonstrate small explosives to students around a dozen times a year and most secondary schools stock it. Industrially it can be used to weld railway lines together.
Mr Ball said an investigation had been carried out by Calderdale Council's health and safety department which reported the school had complied with all the procedures for dealing with the chemical and the teacher supervision was in excess of what was required.
Anyone with information should contact Calderdale police on 0845 6060606.
