The existing information supports the use of this material as described in this safety assessment. 4-(2,6,6-Trimethyl-2-cyclohexen)-2-methylbutanal was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that 4-(2,6,6-trimethyl-2-cyclohexen)-2-methylbutanal is not genotoxic. The repeated dose, reproductive, and local respiratory toxicity endpoints were evaluated using the Threshold of Toxicological Concern (TTC) for a Cramer Class I material, and the exposure to 4-(2,6,6-trimethyl-2-cyclohexen)-2-methylbutanal is below the TTC (0.03 mg/kg/day, 0.03 mg/kg/day, and 1.4 mg/day, respectively). Data provided 4-(2,6,6-trimethyl-2-cyclohexen)-2-methylbutanal a No Expected Sensitization Induction Level (NESIL) of 1100 μg/cm2 for the skin sensitization endpoint. The phototoxicity/photoallergenicity endpoints were evaluated based on data and ultraviolet/visible (UV/Vis) spectra; 4-(2,6,6-trimethyl-2-cyclohexen)-2-methylbutanal is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; 4-(2,6,6-trimethyl-2-cyclohexen)-2-methylbutanal was found not to be Persistent, Bioaccumulative, and Toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1.