To support the evaluation of non-animal approaches for skin sensitization assessment, scientists from CPSC, FDA, and NICEATM worked with industry and international collaborators to collect human predictive patch test data from approximately 1800 publications. Results considered to be sufficiently reliable were classified using GHS categories. Decision tree and weight-of-evidence approaches were used to help resolve ambiguity and discordance in individual tests for each substance. This classification approach was applied to a Cosmetics Europe reference list of 128 substances to support the evaluation of defined approaches for skin sensitization proposed for inclusion in a new OECD guideline, for which reliable classifications were obtained for 80 substances. Results of the analysis were described in an abstract (Strickland et al.) accepted for presentation at the 2020 Society of Toxicology Annual Meeting. The entire human skin sensitization patch test database will be made publicly available in the future for additional evaluation of alternative skin sensitization methods and development of new models.