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Proceedings Paper

SPF determination of sunscreens with UV-LED (Conference Presentation)
Author(s): Jürgen Lademann

Paper Abstract

Based on the changed leisure behavior, that means on the fact that vacationers spend their free time more and more in the mountains or in sunny regions by the sea, the use of sunscreen is of particular importance. The effectiveness of sunscreens against harmful UV radiation from the sun is characterized by the sun protection factor (SPF). For its determination, the minimum erythema dose, i.e. the dose of UV radiation causing sunburn in case of unprotected skin and sunscreen-treated skin is used. Thereby a sunburn is generated, which actually should be prevented by the sunscreen. This method is therefore unsatisfactory. The American Food and Drug Administration and the European Commission have been calling for the development of a non-invasive method for the determination of sun protection factors of sunscreens for years. At the Charité, a physical, non-invasive method for the determination of sunscreens was developed in cooperation with Courage Khazaka GmbH and Hans Karrer GmbH. The measuring method used here is based on the so-called "photon banana". UV radiation is applied to the sunscreen-treated skin through an optical fiber. Parts of the light are reflected, other parts are scattered in the tissue and emerge elsewhere. This light passes "banana-shaped" through the upper skin layer and passes through the sunscreen twice. It is detected with optical fibers and a detector. The excitation occurs using LEDs. Very good correlations between the measured SPF values and the SPF values determined in the test laboratories under in vivo conditions could be achieved.

Paper Details

Date Published: 4 March 2019
Proc. SPIE 10877, Dynamics and Fluctuations in Biomedical Photonics XVI, 108770Q (4 March 2019); doi: 10.1117/12.2509704
Show Author Affiliations
Jürgen Lademann, Charité Universitätsmedizin Berlin (Germany)

Published in SPIE Proceedings Vol. 10877:
Dynamics and Fluctuations in Biomedical Photonics XVI
Valery V. Tuchin; Martin J. Leahy; Ruikang K. Wang, Editor(s)

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