A new study has raised fears of an increase in skin cancer after revealing a 30% rise in the number of private sunbeds.
It also found that the beds are getting more powerful, as 83% produce UVB radiation levels that exceed the European standard.
Scientists at the Ninewells Hospital & Medical School in Dundee made their findings after comparing current sunbed usage with a 1998 survey of sunbeds in the Dundee, Perth and Kinross areas.
The researchers also conducted a survey of sunbed users and discovered that 15% believe the machines do not carry a health risk.
Half of the people questioned began using the beds before they were aged 24, and almost a quarter have been using sunbeds for more than 10 years.
More than a third have had between 29 and 40 sunbed sessions in the past year, and a quarter never use goggles to protect their eyes, the study published in the British Journal of Dermatology claims.
Dr Harry Moseley, one of the study's authors, said: "In an earlier study we found that sunbeds carried a cancer risk similar to that of UK summer sun.
"However, since our initial study, there have been technological developments leading to new, high power 'fast tan' units. These have become increasingly popular, along with the emergence of unmanned sun parlours.
"People sometimes use sunbeds in the mistaken belief that they are a safe alternative to conventional tanning, but this is simply not the case - the average sunbed now carries the same cancer risk as the midday southern European sun."