Two visualizations of the chemical space covered by the 3 different chemical sets analyzed: yellow represents the initial collated list of ∼2,500 chemicals in step 1 of the selection process; black represents the chemicals annotated in the CPCat database as used in cosmetics; and red represents the 38 chemicals tested in this work. (A) Histogram of the 33 most frequent chemotypes present within the 3 chemical lists. Most chemotypes show an even representation, apart from linear alkane chains that are comparatively underrepresented in the test chemical list. (B) t-SNE visualization of the chemical space covered by the different chemical lists. The region on the right-hand side with no representation in the test chemical set, largely represents chemicals with long alkane chains which corresponds with the chemotype frequency analysis.