The UV portion of mid-day summer sunlight is made up of about 95% UVA light and 5% UVB light. The majority of tanning lamps in sunbeds emit essentially the same mixture, but with higher intensity, usually 2-3 times more intense. That’s why professional tanning salons control the duration of your exposure – short sessions that typically only last a few minutes – based on the UV output of the sunbed and your individual skin type and tanning history. Generally, the higher the intensity of a sunbed, the shorter the session.
Intensity x Time Exposed = Total Exposure
It’s simple math. Your total exposure to the sun or a sunbed is based on the intensity of the UV light multiplied by the total exposure time. So if the sunbed you’re using is two times more powerful than sunlight, your tanning professional uses a recommended exposure schedule as a tool to carefully assign your exposure time. Sunbeds with higher intensity generally have shorter exposure times.
It’s a protocol calculated to deliver three-quarters-or-less of what would induce a sunburn for your skin type. For millions of Americans, this system is the best way to gradually build a “base tan” which, combined with sunscreen usage outdoors, helps prevent sunburn.
The photo-protection of a suntan, in proper combination with sunscreen outdoors, is more protective against sunburn than sunscreen use alone – which is why many practice the responsible usage of sunbeds.