A new device could help to vastly improve safety for lone tradesmen, such as plumbers or gas fitters, who carry out the majority of their work on their own.

Craig Swallow's technology company, Connexion2, has designed the 'lone worker' alarm, called 'Identicom', which is disguised as an official identification badge. The alarm came about following an employee safety conference in 2002, which was held by the Suzy Lamplugh Trust. Ms Lamplugh, an estate agent, went missing after she visited a client alone in the late 1980s. She has never been found.

Until now, the provision of buddy systems, where employees are paired to share location details, and mobile phones have been the main source of lone worker protection.

However, this new alarm is heralding a new era for lone worker safety and could potentially be rolled out to all tradesmen who work solo.

When a lone worker arrives at a job, they can press a button on the alarm to alert a 24/7 call centre to their whereabouts and to any potential risks they may see, such as a noisy dog or a lack of lighting. Mr Swallow told The Telegraph: “These other functions are more proactive than the reactive push of the button to alert the police and record the incident.

“The device almost trains the worker to assess risk, as opposed to just walking blind into a situation”, he added.

Companies that have already given their workers the alarm include broadcaster BSkyB and Travelodge.