A glow in the dark device has been developed that could save the lives of up to 3,000 acute asthma sufferers every year, it emerged today

The luminous inhaler cap uses man-made photo-fluorescent crystals that need just eight minutes of exposure to daylight to stay illuminated for 18 hours.

Inventor Grant Taylor, from Telford, Shropshire, came up with the idea by accident after a delivery of crystals was spilled on the carpet. Some crystals remained even after cleaning the floor and glowed when the lights were turned off.

Mr Taylor, development and marketing director of Innovative Business Solutions 2000, based in the West Midlands, said: "This is an innovation that can save lives. It's estimated that over 3,000 people a year worldwide die from not being able to find their inhaler in the dark during acute asthma attacks."

The crystals have an average lifespan of up to 12 years.

Used as an additive, the crystal technology can make plastics, inks and textiles glow in a variety of colours - and could be used across a broad range of devices in the medical industry, according to Mr Taylor.

He is now looking to market the idea with the help of regional development agency Advantage West Midlands.

"Any critical care emergencies that require night-time doses - such as heart medication, diabetic insulin or the contents of roadside medical boxes - would benefit from this additive," he said.

Catherine Smith, head of health policy at Advantage West Midlands, said: "This is a great innovation which will benefit thousands of asthma sufferers across the UK and even overseas."

Products already manufactured using the crystals include life hammers, which are used to smash car and rail carriage glass in emergencies, Swiss army knives, fire extinguishers and diving torches.