Suntanning with sunscreens: a comparison with sunbed tanning

Summary Background/Purpose Acquiring a tanned skin, either by sunbathing, sunbed use, or a combination of both, is a desirable objective for many people. The objective here was to compare the ultraviolet (UV) exposure resulting from a 2-week vacation spent sunbathing with sunscreen-protected skin, with that from a typical course of 10 sessions on a sunbed. Methods A numerical analysis combining data on sunlight and sunbed UV levels, time spent tanning and spectral absorption properties of different types of sunscreen. Results The analysis showed that unless a sunscreen provides optimal broad-spectrum protection, a 2-week sunbathing vacation that avoids sunburn on sunscreen-protected skin can result in a higher cumulative UV exposure than a typical 10-session sunbed course. The lowest exposures for a given sun protection factor (SPF) are obtained when sunscreen delivers broad-spectrum protection that approaches the ideal of uniform absorption at all wavelengths throughout the UV spectrum. Conclusion In extreme cases of recreational sun exposure where sunscreens providing suboptimal broad-spectrum protection are used, the UV insult to the skin is likely to result in higher cumulative exposures than commonly employed sunbed practices.