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Accumulation of sunscreen in human skin after daily applications: a study of sunscreens with different ultraviolet radiation filters
Author(s) -
Bodekær Mette,
Åkerström Ulf,
Wulf Hans Christian
Publication year - 2012
Publication title -
photodermatology, photoimmunology and photomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.736
H-Index - 60
eISSN - 1600-0781
pISSN - 0905-4383
DOI - 10.1111/j.1600-0781.2012.00651.x
Subject(s) - sun protection factor , sun protection , ultraviolet radiation , ultraviolet a , sun exposure , dermatology , medicine , ultraviolet , sunscreening agents , chemistry , skin cancer , materials science , optoelectronics , cancer , radiochemistry
Summary Background/Purpose Sunscreen applied to the skin provides a considerable sun protection factor ( SPF ) even after 8 h. Sunscreen use for consecutive days may therefore result in an accumulation of the product. This study investigated the consequences of accumulation for SPF . Methods Two sunscreens, one containing organic and one containing particle ultraviolet radiation (UVR) filters ( SPF 30) (2 mg/cm 2 ), were used. Areas on the back of 22 volunteers were applied with sunscreen on 5 consecutive days, once daily (12 volunteers) and three times daily (10 volunteers), and phototested. The SPF was determined on Days 1, 3 and 5. Results One daily application of sunscreen did not result in an accumulation in the skin that significantly affected the SPF . However, three daily applications provided a significantly higher SPF for both the organic (mean SPF 1.56) and particle (mean SPF 2.45) sunscreen at Day 5 compared to Day 1 ( P = 0.023 for both sunscreens). Conclusion Sunscreens accumulate in the skin when applied in the recommended amounts three times daily. In conjunction with other sun protection strategies, sunscreen application on consecutive days prior to UVR exposure can result in a basic skin protection, which may help to prevent severe sunburns on sun holidays.