20/01/2017 16:47 GMT | Updated 20/01/2017 17:06 GMT

Bomb Squads Perform Almost 600 Controlled Explosions At Schools Due To 'Dangerous' Chemical

The chemical is potentially explosive if it dries out.

Bomb disposal teams performed almost 600 controlled explosions at schools in just two months after the government reissued warnings about a potentially dangerous chemical

The army was called to hundreds of secondaries over the chemical 2,4 dinitrophenylhydrazine (DNPH), which was recently added to the A Level chemistry syllabus. 

While perfectly safe when stored in water, DNPH is potentially explosive if it is allowed to dry out, the Department for Education warned schools. 

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The chemical was recently added to the A Level chemistry syllabus 

Ministry of Defence (MoD) figures obtained by the BBC show that 589 controlled explosions were carried out between October and December 2016 after government advice was issued. 

Dr David Kinnison, a chemical safety advisor from the University of Southampton, said schools had done “exactly as they were instructed”. 

“As a safety professional, I would always err on the side of caution,” Kinnison told the BBC. 

“Yes, there could have been possible other ways of dealing with this, however, the schools were presented with this advice.

“The positive is that a material which potentially could be unsafe was made safe, and the bomb disposal squads have gained some valuable experience.” 

However, some schools have been criticised for not warning local residents about the bomb squad blasts. 

Thomas Adams School in Shropshire was forced to apologise after the chemical was disposed of on the school playing field without warning on Halloween evening. 

A woman named Fiona Rothwell told the Shropshire Star: “Many elderly and very young people have been scared tonight. The noise was immense and very worrying.

“I do feel this could have been avoided with some advance warning - especially choosing Halloween to do it,” she added. 

According to MoD figures, controlled explosions in England cost just under £90,000. The amount in other areas is still being calculated.