Photobiological evaluation of ultraviolet sunbeds

Seven different types of sunbeds frequently used in Europe were photobiologically evaluated by analysis of four characteristics: (1) the exposure time to get I SED (Standard Erythema Dose), (2) the sun effect factor comparing the efficiency of the device to that of the reference sun, (3) the effect/erythema ratio comparing the efficiency of a particular effect to erythema efficiency, and (4) the beneficial/damaging effect ratio comparing the efficiency of a beneficial effect to the efficiency of a damage directly. Concerning their ability to stimulate wanted effects or hazards, the devices under investigation exhibited large variations. Most of the sunbeds showed a satisfactory ratio regarding their efficiency of direct and delayed pigmentation relative to their risk of skin cancer and erythema formation. Only one device was found to be suitable to stimulate vitamin D-3 synthesis. The majority of the devices evaluated showed extremely high levels of erythema effective irradiance between 24 and 29 SED.h(-1) and had to be classified into the UV types 2, 4 and 5 defined by the International Electrotechnical Commission.