Series of Papers Published on Comparison of SPF Testing Methods

On 1 September 2025, leading experts in sun protection published a series of papers outlining the comparison and statistical analysis of five methods to test the Sun Protection Factor (SPF) of cosmetic products.  These papers are publicly accessible from the International Journal of Cosmetic Science.  Below is the list of published papers.

• Are there alternatives to the traditional in-vivo SPF test (ISO 24444)? Comparison and statistical analysis of 5 proposed methods - https://onlinelibrary.wiley.com/doi/epdf/10.1111/ics.70026
• Colson et al., Test design and results of a method performance characterization study for SPF and UVA-PF testing - https://onlinelibrary.wiley.com/doi/epdf/10.1111/ics.70019
• Cole et al., The variability of in vivo sunscreen sun protection factor values - https://onlinelibrary.wiley.com/doi/epdf/10.1111/ics.70000
• Pouradier et al., Performance assessment of the Double Plate method(ISO23675) in ALT-SPF Consortium: A highly reproducible and accurate in vitro method to determine SPF - https://onlinelibrary.wiley.com/doi/epdf/10.1111/ics.13088
• Ruvolo et al., Performance of hybrid diffuse reflectance spectroscopy(HDRS- ISO 23698) methodology for assessment of sunscreen protection in the ALT-SPF Consortium validation study - https://onlinelibrary.wiley.com/doi/epdf/10.1111/ics.13089
• Kunze et al., The ALT-SPF ring study—Correlation in silico versus in vivo SPF ISO24444 and in vitro UVA-PF ISO24443 - https://onlinelibrary.wiley.com/doi/epdf/10.1111/ics.13086
• Reble et al., Characterization of LED-based hybrid diffuse reflectance spectroscopy method for determination of SPF and UVA-PF in blinded multi-centre study (ALT-SPF) - https://onlinelibrary.wiley.com/doi/epdf/10.1111/ics.70007
• Acker et al., The ALT-SPF ring study – in vitro determination of the SPF & UVA-PF by the fused method - https://onlinelibrary.wiley.com/doi/epdf/10.1111/ics.70015