A portable panic button which allows teachers to alert colleagues if they are being threatened or attacked is to be marketed to schools.
The pound;250 device is designed to look like an identity card holder. It can be worn around the neck or attached to clothing and can be activated surreptitiously.
It uses mobile phone technology to communicate with a call centre in Sheffield, which can record abusive comments or pass requests for back-up on to staff at the teacher's school.
Trials for the Identicom began in hospitals last week. Connexion2, the south Yorkshire company which developed the device, is confident it will become a fixture in schools because of concerns about violence against staff.
Mike Wilson, an RE teacher who had three ribs broken when he was attacked by a 15-year-old pupil three years ago, thinks the device would be helpful but needs extensive testing in the classroom.
"Children like grabbing things, which is why male teachers in some special schools don't wear ties," said Mr Wilson, who works at Grove special school in Northumberland.
"Because this device is activated by a rip cord there could be a danger of false alarms."
Chris Keates, acting general secretary of the National Association of Schoolmasters Union of Women Teachers, said there was some merit in introducing panic buttons for teachers who worked in isolation. But she was uncertain whether the Identicom system would provide a fast enough response.
She said: "Any system would need detailed consideration to ensure that public money is not being used to make profits for private companies trading on fear and insecurity."
Polls by the NASUWT suggest that a member of school staff is assaulted every seven minutes. However, evidence from the British Crime Survey indicates that attacks on teachers have fallen by more than 40 per cent over the past eight years.
School staff are three times less likely to be assaulted than nurses.
For more information: www.connexion2.com