scientists have warned that most sunbeds expose users to double the radiation safety limits, increasing the risk of skin cancer.

Tests by a team from Dundee University found hundreds exceeded EU laws, which set Ultraviolet (UV) radiation limits at 0.3 watts per square metre (Wm2).

It checked 402 sunbeds between October 2010 and February 2011 and found only 10% complied with the safety limits. The rest had average UV radiation levels of around 0.6Wm2. The findings have been rejected by the body representing manufacturers as outdated.

Professor Harry Moseley, the university's consultant medical physicist who led the project, said: "The development of high-power sunlamps, along with clear failures of the sunbed industry to regulate itself effectively, is putting young people at an even greater risk of skin cancer than we previously thought.

"We hope these findings will make people think twice before using sunbeds as you can't be sure how much radiation you're exposing yourself to."

However, the Sunbed Association said the study was two years out of date and that all new units manufactured since April 2009, when the level was introduced, are compliant. Its chairman, Gary Lipman, said the group had been working with "its members, non-members and the enforcement departments within local authorities to inform about the change in UV emission levels".

Cancer Research UK funded the research, which is published in the British Journal of Dermatology. The charity's senior health information officer Yinka Ebo said: "It's worrying to see that so many sunbeds are not meeting the safety standards. This strengthens our advice that using a sunbed just isn't worth it."