This Annual Review of Cosmetic Ingredient Safety Assessments updates and affirms the findings of the Cosmetic Ingredient Review (CIR) Expert Panel's assessment of almost 30 compounds used in cosmetic ingredients. The review also summarizes new findings from epidemiology studies of hair dyes. The CIR Expert Panel's re-review process is intended to uncover any new data since the last safety assessment. In some cases, newly available data are largely redundant compared with the data available in the original safety assessment. In other cases, new data present new safety issues. If after considering the newly available information, the CIR Expert Panel decides to not reopen a safety assessment, this finding, along with any background material, is summarized and announced publicly. To assure that the scientific community is aware of any new information and the decision not to reopen, this Annual Review of Cosmetic Ingredient Safety Assessments is prepared. A list of reference sources is provided after each ingredient re-review summary that updates the available published literature and includes any unpublished data made available since the original safety assessment. The re-review also captures information on the industry's current practices of ingredient use, updating the data available in the earlier report. Although this material provides the opinion of the CIR Expert Panel regarding the new data described, it does not constitute a full safety review. The CIR Expert Panel has assessed the safety of over 2100 cosmetic ingredients since its inception in 1976. These safety assessments were published in the