Overview of proficiency testing results for the in vivo determination of sun protection factor.

A sunscreen product is allowed to be marketed if a protection is provided against ultraviolets (UV) including UVA rays and UVB rays expressed by the sun protection factor (SPF). UVB is radiation that is in the region of the ultraviolet spectrum which extends from about 290 to 320 nm in wavelength and that is primarily responsible for sunburn, ageing of the skin, and the development of skin cancer. Thus, since April 2009, the Bureau Interprofessionnel d'Etudes Analytiques (BIPEA) set up a proficiency testing scheme (PTS) for the determination of SPF in vivo of sunscreen products according to ISO 24444 standard [Cosmetics - Sun protection test methods - in vivo determination of the sun protection factor (SPF)] to evaluate the analytical performances of laboratories on these analyses.

Nuclear and Urinary Measurements Show the Efficacy of Sun-Protection Factor 50+ Sunscreen against DNA Photoproducts upon Real-Life Recreational Exposure.

Sunscreens have been shown to protect against UVR-induced DNA damage in human skin under laboratory conditions. We presently extended these observations to real-life conditions in volunteers after their ordinary exposure habits during summer holidays. Volunteers were randomly assigned to a control group and an educated group supplied with a SPF ≥50 sunscreen and receiving instructions for use.

In vivo evaluation of sunscreen application by multispectral imaging: A new tool for educating sunscreen users.

Background: The sun protection factor (SPF) of sunscreens is evaluated using standardized protocols based on the application of 2 mg/cm of product. However, the amount of product applied by sunscreen users in real life is likely to be much lower.

Objectives: To evaluate a new multispectral imaging approach for determining the actual quantity of sunscreen applied by users and to assess the benefits of an application guide for the use of an SPF 50+ sunscreen.

DNA photoproducts released by repair in biological fluids as biomarkers of the genotoxicity of UV radiation.

UV-induced formation of photoproducts in DNA is a major initiating event of skin cancer. Consequently, many analytical tools have been developed for their quantification in DNA. In the present work, we extended our previous liquid chromatography-mass spectrometry method to the quantification of the short DNA fragments containing photoproducts that are released from cells by the repair machinery.